get-countries.ts

const locales = ['cs', 'hu', 'pl', 'ro', 'sk', 'en']
const countries = ['CZ', 'HU', 'PL', 'RO', 'SK', 'US']

export async function fetchTerritories(locale: string) {
  const response = await fetch(`https://raw.githubusercontent.com/unicode-org/cldr-json/main/cldr-json/cldr-localenames-full/main/${locale}/territories.json`)
  const json = await response.json() as Record<string, Record<string, Record<string, Record<string, Record<string, string>>>>>
  return json.main[locale].localeDisplayNames.territories
}

// get translations from all locales for all territories
export async function getTerritories() {
  const territories = {} as Record<string, Record<string, string>>
  for (const locale of locales) {
    const localeTerritories = await fetchTerritories(locale)
    for (const territory in localeTerritories) {
      territories[territory] = {
        ...territories[territory],
        [locale]: localeTerritories[territory],
      }
    }
  }
  return territories
}

(async () => {
  const territories = await getTerritories()

  const countriesTerritories = {} as Record<string, Record<string, string>>
  for (const locale of locales) {
    for (const country of countries) {
      countriesTerritories[locale] = {
        ...countriesTerritories[locale],
        [country]: territories[country][locale],
      }
    }
  }

  console.log(JSON.stringify(countriesTerritories, null, 2))
})()