diff --git a/data/countries-gr.json b/data/countries-el.json
similarity index 99%
rename from data/countries-gr.json
rename to data/countries-el.json
index 924dbf2..03e7a4f 100644
--- a/data/countries-gr.json
+++ b/data/countries-el.json
@@ -2,7 +2,7 @@
   {
     "id": "004",
     "name": "Αφγανιστάν",
-    "complete name": "Αφγανιστάν",
+    "completeName": "Αφγανιστάν",
     "officialName": "Η Ισλαμική Δημοκρατία του Αφγανιστάν",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -14,7 +14,7 @@
   {
     "id": "008",
     "name": "Αλβανία",
-    "complete name": "Αλβανία",
+    "completeName": "Αλβανία",
     "officialName": "Η Δημοκρατία της Αλβανίας",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -26,7 +26,7 @@
   {
     "id": "010",
     "name": "Ανταρκτική",
-    "complete name": "Ανταρκτική",
+    "completeName": "Ανταρκτική",
     "officialName": "Ανταρκτική",
     "sovereignty": "Συνθήκη της Ανταρκτικής",
     "iso31661": {
@@ -38,7 +38,7 @@
   {
     "id": "012",
     "name": "Αλγερία",
-    "complete name": "Αλγερία",
+    "completeName": "Αλγερία",
     "officialName": "Η Λαϊκή Δημοκρατία της Αλγερίας",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -50,7 +50,7 @@
   {
     "id": "016",
     "name": "Αμερικανική Σαμόα",
-    "complete name": "Αμερικανική Σαμόα",
+    "completeName": "Αμερικανική Σαμόα",
     "officialName": "Η Επικράτεια της Αμερικανικής Σαμόα",
     "sovereignty": "Ηνωμένες Πολιτείες",
     "iso31661": {
@@ -62,7 +62,7 @@
   {
     "id": "020",
     "name": "Ανδόρα",
-    "complete name": "Ανδόρα",
+    "completeName": "Ανδόρα",
     "officialName": "Το Πριγκιπάτο της Ανδόρας",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -74,7 +74,7 @@
   {
     "id": "024",
     "name": "Ανγκόλα",
-    "complete name": "Ανγκόλα",
+    "completeName": "Ανγκόλα",
     "officialName": "Η Δημοκρατία της Ανγκόλα",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -86,7 +86,7 @@
   {
     "id": "028",
     "name": "Αντίγκουα και Μπαρμπούντα",
-    "complete name": "Αντίγκουα και Μπαρμπούντα",
+    "completeName": "Αντίγκουα και Μπαρμπούντα",
     "officialName": "Αντίγκουα και Μπαρμπούντα",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -98,7 +98,7 @@
   {
     "id": "031",
     "name": "Αζερμπαϊτζάν",
-    "complete name": "Αζερμπαϊτζάν",
+    "completeName": "Αζερμπαϊτζάν",
     "officialName": "Η Δημοκρατία του Αζερμπαϊτζάν",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -110,7 +110,7 @@
   {
     "id": "032",
     "name": "Αργεντινή",
-    "complete name": "Αργεντινή",
+    "completeName": "Αργεντινή",
     "officialName": "Η Αργεντινή Δημοκρατία",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -122,7 +122,7 @@
   {
     "id": "036",
     "name": "Αυστραλία",
-    "complete name": "Αυστραλία",
+    "completeName": "Αυστραλία",
     "officialName": "Η Κοινοπολιτεία της Αυστραλίας",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
@@ -134,7 +134,7 @@
   {
     "id": "040",
     "name": "Αυστρία",
-    "complete name": "Αυστρία",
+    "completeName": "Αυστρία",
     "officialName": "Η Δημοκρατία της Αυστρίας",
     "sovereignty": "Μέλος του ΟΗΕ",
     "iso31661": {
diff --git a/data/countries-en.json b/data/countries-en.json
index c1868d7..e6565df 100644
--- a/data/countries-en.json
+++ b/data/countries-en.json
@@ -2,7 +2,7 @@
   {
     "id": "004",
     "name": "Afghanistan",
-    "complete name": "Afghanistan",
+    "completeName": "Afghanistan",
     "officialName": "The Islamic Republic of Afghanistan",
     "sovereignty": "UN member",
     "iso31661": {
@@ -14,7 +14,7 @@
   {
     "id": "008",
     "name": "Albania",
-    "complete name": "Albania",
+    "completeName": "Albania",
     "officialName": "The Republic of Albania",
     "sovereignty": "UN member",
     "iso31661": {
@@ -26,7 +26,7 @@
   {
     "id": "010",
     "name": "Antarctica",
-    "complete name": "Antarctica",
+    "completeName": "Antarctica",
     "officialName": "Antarctica",
     "sovereignty": "Antarctic Treaty",
     "iso31661": {
@@ -38,7 +38,7 @@
   {
     "id": "012",
     "name": "Algeria",
-    "complete name": "Algeria",
+    "completeName": "Algeria",
     "officialName": "The People's Democratic Republic of Algeria",
     "sovereignty": "UN member",
     "iso31661": {
@@ -50,7 +50,7 @@
   {
     "id": "016",
     "name": "American Samoa",
-    "complete name": "American Samoa",
+    "completeName": "American Samoa",
     "officialName": "American Samoa",
     "sovereignty": "United States",
     "iso31661": {
@@ -62,7 +62,7 @@
   {
     "id": "020",
     "name": "Andorra",
-    "complete name": "Andorra",
+    "completeName": "Andorra",
     "officialName": "The Principality of Andorra",
     "sovereignty": "UN member",
     "iso31661": {
@@ -74,7 +74,7 @@
   {
     "id": "024",
     "name": "Angola",
-    "complete name": "Angola",
+    "completeName": "Angola",
     "officialName": "The Republic of Angola",
     "sovereignty": "UN member",
     "iso31661": {
@@ -86,7 +86,7 @@
   {
     "id": "028",
     "name": "Antigua and Barbuda",
-    "complete name": "Antigua and Barbuda",
+    "completeName": "Antigua and Barbuda",
     "officialName": "Antigua and Barbuda",
     "sovereignty": "UN member",
     "iso31661": {
@@ -98,7 +98,7 @@
   {
     "id": "031",
     "name": "Azerbaijan",
-    "complete name": "Azerbaijan",
+    "completeName": "Azerbaijan",
     "officialName": "The Republic of Azerbaijan",
     "sovereignty": "UN member",
     "iso31661": {
@@ -110,7 +110,7 @@
   {
     "id": "032",
     "name": "Argentina",
-    "complete name": "Argentina",
+    "completeName": "Argentina",
     "officialName": "The Argentine Republic",
     "sovereignty": "UN member",
     "iso31661": {
@@ -122,7 +122,7 @@
   {
     "id": "036",
     "name": "Australia",
-    "complete name": "Australia",
+    "completeName": "Australia",
     "officialName": "The Commonwealth of Australia",
     "sovereignty": "UN member",
     "iso31661": {
@@ -134,7 +134,7 @@
   {
     "id": "040",
     "name": "Austria",
-    "complete name": "Austria",
+    "completeName": "Austria",
     "officialName": "The Republic of Austria",
     "sovereignty": "UN member",
     "iso31661": {
diff --git a/package-lock.json b/package-lock.json
index 72c6f5a..92dcd2b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@tsevdos/el-utils",
-  "version": "0.6.0",
+  "version": "0.7.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@tsevdos/el-utils",
-      "version": "0.6.0",
+      "version": "0.7.0",
       "license": "MIT",
       "devDependencies": {
         "@changesets/changelog-github": "^0.5.0",
diff --git a/src/__tests__/geoUtils.test.ts b/src/__tests__/geoUtils.test.ts
index a3f9796..2791350 100644
--- a/src/__tests__/geoUtils.test.ts
+++ b/src/__tests__/geoUtils.test.ts
@@ -9,6 +9,8 @@ import prefecturesEl from "../../data/prefectures-el.json";
 import prefecturesEn from "../../data/prefectures-en.json";
 import taxOfficesEl from "../../data/taxOffices-el.json";
 import taxOfficesEn from "../../data/taxOffices-en.json";
+import countriesEl from "../../data/countries-el.json";
+import countriesEn from "../../data/countries-en.json";
 import {
   MOUNT_ATHOS_PREFECTURE_ID,
   MOUNT_ATHOS_REGION_ID,
@@ -35,6 +37,9 @@ import {
   getTaxOfficesByUnitId,
   searchCityByName,
   searchTaxOffice,
+  getCountries,
+  searchCountryByName,
+  getCountry,
 } from "../geoUtils";
 
 const administrativeRegions = { el: administrativeRegionsEl, en: administrativeRegionsEn };
@@ -45,11 +50,13 @@ const administrativeRegionsWithoutMountAthos = {
 const cities = { el: citiesEl, en: citiesEn };
 const geographicRegions = { el: geographicRegionsEl, en: geographicRegionsEn };
 const prefectures = { el: prefecturesEl, en: prefecturesEn };
-export const prefecturesWithoutMountAthos = {
+const prefecturesWithoutMountAthos = {
   el: prefectures.el.filter(({ id }) => id !== MOUNT_ATHOS_PREFECTURE_ID),
   en: prefectures.en.filter(({ id }) => id !== MOUNT_ATHOS_PREFECTURE_ID),
 };
 
+const allCountries = { el: countriesEl, en: countriesEn } as const;
+
 describe("getAdministrativeRegions", () => {
   it("correctly returns data with default values (in greek language)", () => {
     const expectedData = administrativeRegionsWithoutMountAthos.el;
@@ -1481,3 +1488,158 @@ describe("searchTaxOffice", () => {
     ]);
   });
 });
+
+describe("getCountries", () => {
+  it("correctly returns data with default values (in greek language)", () => {
+    const expectedData = allCountries.el;
+
+    expect(getCountries()).toEqual(expectedData);
+    expect(getCountries({ locale: "el" })).toEqual(expectedData);
+    expect(getCountries().length).toEqual(249);
+  });
+
+  it("correctly returns data (in english language)", () => {
+    const expectedData = allCountries.en;
+
+    expect(getCountries({ locale: "en" })).toEqual(expectedData);
+    expect(getCountries({ locale: "en" }).length).toEqual(249);
+  });
+});
+
+describe("searchCountryByName", () => {
+  it("given the search term 'Ελλάδα', returns Greece (in greek language)", () => {
+    const greeceIndex = allCountries.el.findIndex(({ name }) => name === "Ελλάδα");
+
+    expect(searchCountryByName({ searchTerm: "Ελλάδα" })).toEqual([allCountries.el[greeceIndex]]);
+    expect(searchCountryByName({ searchTerm: "Ελλάδα" })?.length).toBe(1);
+  });
+
+  it("given the search term 'ελλα', returns Greece (in greek language)", () => {
+    const greeceIndex = allCountries.el.findIndex(({ name }) => name === "Ελλάδα");
+
+    expect(searchCountryByName({ searchTerm: "ελλα", locale: "el" })).toEqual([allCountries.el[greeceIndex]]);
+    expect(searchCountryByName({ searchTerm: "ελλα", locale: "el" })?.length).toBe(1);
+  });
+
+  it("given the search term 'ηνωμε', returns all (7) the correct countries (in greek language)", () => {
+    const expectedCountries = [
+      {
+        id: "484",
+        name: "Μεξικό",
+        completeName: "Μεξικό",
+        officialName: "Οι Ηνωμένες Μεξικανικές Πολιτείες",
+        sovereignty: "Μέλος του ΟΗΕ",
+        iso31661: { A2: "MX", A3: "MEX" },
+        tld: ".mx",
+      },
+      {
+        id: "581",
+        name: "Απομακρυσμένες Νησίδες των Ηνωμένων Πολιτειών",
+        completeName: "Απομακρυσμένες Νησίδες των Ηνωμένων Πολιτειών",
+        officialName:
+          "Νήσος Μπέικερ, Νήσος Χάουλαντ, Νήσος Τζάρβις, Ατόλη Τζόνστον, Ύφαλος Κίνγκμαν, Ατόλη Μίντγουεϊ, Νήσος Ναβάσσα, Ατόλη Παλμίρα, και Νήσος Γουέικ",
+        sovereignty: "Ηνωμένες Πολιτείες",
+        iso31661: { A2: "UM", A3: "UMI" },
+        tld: "[af]",
+      },
+      {
+        id: "784",
+        name: "Ηνωμένα Αραβικά Εμιράτα",
+        completeName: "Τα Ηνωμένα Αραβικά Εμιράτα",
+        officialName: "Τα Ηνωμένα Αραβικά Εμιράτα",
+        sovereignty: "Μέλος του ΟΗΕ",
+        iso31661: { A2: "AE", A3: "ARE" },
+        tld: ".ae",
+      },
+      {
+        id: "826",
+        name: "Ηνωμένο Βασίλειο",
+        completeName: "Το Ηνωμένο Βασίλειο της Μεγάλης Βρετανίας και Βόρειας Ιρλανδίας",
+        officialName: "Το Ηνωμένο Βασίλειο της Μεγάλης Βρετανίας και Βόρειας Ιρλανδίας",
+        sovereignty: "Μέλος του ΟΗΕ",
+        iso31661: { A2: "GB", A3: "GBR" },
+        tld: ".gb",
+      },
+      {
+        id: "834",
+        name: "Τανζανία",
+        completeName: "Η Ηνωμένη Δημοκρατία της Τανζανίας",
+        officialName: "Η Ηνωμένη Δημοκρατία της Τανζανίας",
+        sovereignty: "Μέλος του ΟΗΕ",
+        iso31661: { A2: "TZ", A3: "TZA" },
+        tld: ".tz",
+      },
+      {
+        id: "840",
+        name: "Ηνωμένες Πολιτείες της Αμερικής",
+        completeName: "Οι Ηνωμένες Πολιτείες της Αμερικής",
+        officialName: "Οι Ηνωμένες Πολιτείες της Αμερικής",
+        sovereignty: "Μέλος του ΟΗΕ",
+        iso31661: { A2: "US", A3: "USA" },
+        tld: ".us",
+      },
+      {
+        id: "850",
+        name: "Παρθένοι Νήσοι",
+        completeName: "Παρθένοι Νήσοι (ΗΠΑ)",
+        officialName: "Οι Παρθένοι Νήσοι των Ηνωμένων Πολιτειών",
+        sovereignty: "Ηνωμένες Πολιτείες",
+        iso31661: { A2: "VI", A3: "VIR" },
+        tld: ".vi",
+      },
+    ];
+
+    expect(searchCountryByName({ searchTerm: "ηνωμε" })).toEqual(expectedCountries);
+    expect(searchCountryByName({ searchTerm: "ηνωμε" })?.length).toBe(7);
+  });
+});
+
+describe("getCountry", () => {
+  it("correctly returns a country with specific id (in greek language)", () => {
+    expect(getCountry({ locale: "el", type: "id", value: "300" })).toEqual(allCountries.el[87]);
+    expect(getCountry({ locale: "el", type: "id", value: "840" })).toEqual(allCountries.el[239]);
+    expect(getCountry({ locale: "el", type: "id", value: "826" })).toEqual(allCountries.el[234]);
+  });
+
+  it("correctly returns a country with specific iso31661 A2 (in greek language)", () => {
+    expect(getCountry({ locale: "el", type: "iso31661-a2", value: "GR" })).toEqual(allCountries.el[87]);
+    expect(getCountry({ locale: "el", type: "iso31661-a2", value: "US" })).toEqual(allCountries.el[239]);
+    expect(getCountry({ locale: "el", type: "iso31661-a2", value: "GB" })).toEqual(allCountries.el[234]);
+  });
+
+  it("correctly returns a country with specific iso31661 A2 (in greek language)", () => {
+    expect(getCountry({ locale: "el", type: "iso31661-a3", value: "GRC" })).toEqual(allCountries.el[87]);
+    expect(getCountry({ locale: "el", type: "iso31661-a3", value: "USA" })).toEqual(allCountries.el[239]);
+    expect(getCountry({ locale: "el", type: "iso31661-a3", value: "GBR" })).toEqual(allCountries.el[234]);
+  });
+
+  it("correctly returns a country with top level domain (in greek language)", () => {
+    expect(getCountry({ locale: "el", type: "tld", value: ".gr" })).toEqual(allCountries.el[87]);
+    expect(getCountry({ locale: "el", type: "tld", value: ".us" })).toEqual(allCountries.el[239]);
+    expect(getCountry({ locale: "el", type: "tld", value: ".gb" })).toEqual(allCountries.el[234]);
+  });
+
+  it("correctly returns a country with specific id (in english language)", () => {
+    expect(getCountry({ locale: "en", type: "id", value: "300" })).toEqual(allCountries.en[87]);
+    expect(getCountry({ locale: "en", type: "id", value: "840" })).toEqual(allCountries.en[239]);
+    expect(getCountry({ locale: "en", type: "id", value: "826" })).toEqual(allCountries.en[234]);
+  });
+
+  it("correctly returns a country with specific iso31661 A2 (in english language)", () => {
+    expect(getCountry({ locale: "en", type: "iso31661-a2", value: "GR" })).toEqual(allCountries.en[87]);
+    expect(getCountry({ locale: "en", type: "iso31661-a2", value: "US" })).toEqual(allCountries.en[239]);
+    expect(getCountry({ locale: "en", type: "iso31661-a2", value: "GB" })).toEqual(allCountries.en[234]);
+  });
+
+  it("correctly returns a country with specific iso31661 A3 (in english language)", () => {
+    expect(getCountry({ locale: "en", type: "iso31661-a3", value: "GRC" })).toEqual(allCountries.en[87]);
+    expect(getCountry({ locale: "en", type: "iso31661-a3", value: "USA" })).toEqual(allCountries.en[239]);
+    expect(getCountry({ locale: "en", type: "iso31661-a3", value: "GBR" })).toEqual(allCountries.en[234]);
+  });
+
+  it("correctly returns a country with top level domain (in english language)", () => {
+    expect(getCountry({ locale: "en", type: "tld", value: ".gr" })).toEqual(allCountries.en[87]);
+    expect(getCountry({ locale: "en", type: "tld", value: ".us" })).toEqual(allCountries.en[239]);
+    expect(getCountry({ locale: "en", type: "tld", value: ".gb" })).toEqual(allCountries.en[234]);
+  });
+});
diff --git a/src/geoUtils.ts b/src/geoUtils.ts
index 34a7265..f831941 100644
--- a/src/geoUtils.ts
+++ b/src/geoUtils.ts
@@ -10,8 +10,11 @@ import prefecturesEn from "../data/prefectures-en.json";
 import taxOfficesEl from "../data/taxOffices-el.json";
 import taxOfficesEn from "../data/taxOffices-en.json";
 import { convertsGreekTextToComparableUpperCase } from "./languageUtils";
+import countriesEl from "../data/countries-el.json";
+import countriesEn from "../data/countries-en.json";
 import {
   City,
+  Country,
   GeographicRegion,
   Municipality,
   Prefecture,
@@ -54,6 +57,8 @@ const prefecturesWithoutMountAthos = {
 
 const allTaxOffices = { el: taxOfficesEl, en: taxOfficesEn } as const;
 
+const allCountries = { el: countriesEl, en: countriesEn } as const;
+
 type Locale = "el" | "en";
 
 type AdministrativeRegionsOptions = {
@@ -256,7 +261,7 @@ export function getCityById(options: CityByIdOptions): City | undefined {
   return citiesData.find((city) => city.id === id);
 }
 
-export type FindByCityRelationsOptions = {
+type CityAdministrativeDivisionOptions = {
   cityId: number;
   locale: Locale;
   entity: "region" | "unit" | "prefecture";
@@ -265,7 +270,7 @@ export type FindByCityRelationsOptions = {
 /**
  * Retrieves related administrative entities for a given city based on the provided options.
  *
- * @param {FindByCityRelationsOptions} options - The options for finding city relations.
+ * @param {CityAdministrativeDivisionOptions} options - The options for finding city relations.
  * @param {number} options.id - The ID of the city to retrieve relations for.
  * @param {string} [options.locale="el"] - The locale to use when retrieving related entities. Defaults to "el".
  * @param {("region"|"unit"|"municipality"|"prefecture")} options.entity - The type of related entity to retrieve.
@@ -273,7 +278,7 @@ export type FindByCityRelationsOptions = {
  * @returns {Region|Unit|RegionWithoutUnits|Prefecture|undefined} - The related entity based on the specified type, or `undefined` if not found.
  */
 export function getCityAdministrativeDivision(
-  options: FindByCityRelationsOptions,
+  options: CityAdministrativeDivisionOptions,
 ): Region | RegionWithoutUnits | Unit | UnitWithoutMunicipalities | Prefecture | undefined {
   const { cityId, locale = "el", entity } = options;
   const city = getCityById({ id: cityId, locale });
@@ -528,10 +533,96 @@ type TaxOfficeOptionsByTerm = { searchTerm: string } & TaxOfficeOptions;
  */
 export function searchTaxOffice(options: TaxOfficeOptionsByTerm): TaxOffice[] {
   const { searchTerm, locale = "el" } = options;
+
   if (searchTerm.trim() === "") return [];
+
   const normalizedTerm = convertsGreekTextToComparableUpperCase(searchTerm);
 
   return allTaxOffices[locale].filter(({ name }) =>
     convertsGreekTextToComparableUpperCase(name).includes(normalizedTerm),
   );
 }
+
+type CountriesOptions = {
+  locale?: Locale;
+};
+
+/**
+ * This function returns all the countries based on the provided options.
+ *
+ * @param {CountriesOptions} [options={}] - The options for the countries.
+ * @param {string} [options.locale="el"] - The locale to use. Default is "el".
+ *
+ * @returns {Country[]} The countries that match the given options, or all countries if no options are provided.
+ */
+export function getCountries({ locale = "el" }: CountriesOptions = {}): Country[] {
+  return allCountries[locale];
+}
+
+type SearchCountryByNameOptions = {
+  locale?: Locale;
+  searchTerm: string;
+};
+
+/**
+ * This function searches for countries by name based on the provided options.
+ *
+ * @param {SearchCountryByNameOptions} options - The options for searching countries by name.
+ * @param {string} [options.locale="el"] - The locale to use. Default is "el".
+ * @param {string} options.searchTerm - The term to search for in country names.
+ *
+ * @returns {Country[] | null} The countries that match the search term, or null if no matches are found.
+ */
+export function searchCountryByName({ locale = "el", searchTerm }: SearchCountryByNameOptions): Country[] | null {
+  const countries = getCountries({ locale });
+  let countriesByName: Country[] = [];
+
+  if (locale === "el") {
+    countriesByName = countries.filter(({ name, completeName, officialName }) => {
+      return (
+        convertsGreekTextToComparableUpperCase(name).includes(convertsGreekTextToComparableUpperCase(searchTerm)) ||
+        convertsGreekTextToComparableUpperCase(completeName).includes(
+          convertsGreekTextToComparableUpperCase(searchTerm),
+        ) ||
+        convertsGreekTextToComparableUpperCase(officialName).includes(
+          convertsGreekTextToComparableUpperCase(searchTerm),
+        )
+      );
+    });
+  }
+
+  if (locale === "en") {
+    countriesByName = countries.filter(({ name, completeName, officialName }) => {
+      return (
+        name.toUpperCase().includes(searchTerm.toUpperCase()) ||
+        completeName.toUpperCase().includes(searchTerm.toUpperCase()) ||
+        officialName.toUpperCase().includes(searchTerm.toUpperCase())
+      );
+    });
+  }
+
+  return countriesByName?.length ? countriesByName : null;
+}
+
+type GetCountryOptions = {
+  locale?: Locale;
+  type: "id" | "iso31661-a2" | "iso31661-a3" | "tld";
+  value: string;
+};
+
+export function getCountry({ locale = "el", type = "id", value = "" }: GetCountryOptions): Country | null {
+  const countries = getCountries({ locale });
+
+  switch (type) {
+    case "id":
+      return countries.find((country) => country.id === value) ?? null;
+    case "iso31661-a2":
+      return countries.find((country) => country.iso31661.A2 === value) ?? null;
+    case "iso31661-a3":
+      return countries.find((country) => country.iso31661.A3 === value) ?? null;
+    case "tld":
+      return countries.find((country) => country.tld === value) ?? null;
+    default:
+      return null;
+  }
+}
diff --git a/src/types.ts b/src/types.ts
index 19b3404..dcf82a3 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -80,3 +80,16 @@ export type City = {
     prefectureId: number;
   };
 };
+
+export type Country = {
+  id: string;
+  name: string;
+  completeName: string;
+  officialName: string;
+  sovereignty: string;
+  iso31661: {
+    A2: string;
+    A3: string;
+  };
+  tld: string;
+};