/**
 * Get the display name of a country from its code.
 * @param code The country code (case insensitive).
 * @returns The country name in English, or 'Unknown' if invalid.
 */
export declare function getCountryName(code: string): string;
/**
 * Check if a country code is valid (has a corresponding flag).
 * @param code The country code (case insensitive).
 * @returns True if valid, false otherwise.
 */
export declare function isValidCountryCode(code: string): boolean;
/**
 * Get all available country codes.
 * @returns An array of all valid country codes in lowercase.
 */
export declare function getAllCountryCodes(): readonly string[];