Is it permissible to break one's fast on the day of arrival in the country of travel, half an hour before the Fajr adhan, given that this period is insufficient to reach the place of residence, and considering the long distance from the country of origin?

If the airport is outside the city limits, travel does not end upon reaching it, but rather upon reaching the built-up area of the city. Therefore, you may avail yourself of the concessions of travel until you reach the built-up area of the city. At that point, you consider:

If you intend to stay for four days or more, you are considered a resident from the moment you arrive in the city, and the concessions of travel cease for you. If you do not intend to stay for four days or more, you are still considered a traveler, and you are permitted to avail yourself of the concessions of travel.

Shaykh Ibn Uthaymeen says: "The rulings of travel begin for a person when he leaves his town, and they end when he enters his town." So, if the airport is outside the town, the traveler is permitted to combine prayers (jama‘), shorten prayers (qasr), and break the fast (fitr) there. However, if it is inside the town, it is not permitted.