Montenegro Airlines' plans to restart operations next month are in jeopardy after the Serbian government explicitly banned the carrier from landing at Belgrade airport.

The Montenegrin airline said on its website that it planned to gradually resume services to the Serbian capital from Podgorica and Tivat during the first half of June. Other international routes are expected to resume after June 15. Montenegro does not have any scheduled domestic flights.

The restart would be made possible by the opening of Montenegro's borders to travellers from certain countries, planned for June 1.

However, the list of approved countries of origin for guests to Montenegro, which includes nine European countries, does not include neighbouring Serbia. This exclusion sparked a diplomatic row between Podgorica and Belgrade. While Serbian Prime Minister Ana Brnabić initially underlined that her government did not believe in retaliation and would not close Serbian borders to Montenegrins, the Serbian Civil Aviation Directorate (CAD) took a much more aggressive stance.

According to Serbian radio B92, the CAD has since issued a directive banning Montenegro Airlines from landing at Belgrade.

"The principle of reciprocity in the movement of passengers between the two countries has been seriously violated, which directly affects the reciprocity clause in the operation of scheduled air transport referred to in Article 13, paragraph 1 of the Ordinance on issuing authorizations to foreign air carriers for international public air transport with the Republic of Serbia, to the detriment of air carriers registered in the Republic of Serbia," the CAD stated in its decision.