Air Astana (KC, Astana Nursultan Nazarbayev) says it has been forced to cancel the launch of its Astana Nursultan Nazarbayev-Ulaanbaatar flights after the Mongolian Civil Aviation Authority (CAAM) unilaterally revoked its flight permits.

The carrier said in a statement that despite having passed a CAAM audit last year and having been granted permission to start the route in March, the regulator suddenly revoked all permits in April.

Air Astana says CAAM's grounds for the revocation which include a lack of airport slots at Ulaanbaatar in June as well as the carrier's alleged blacklisting by the ICAO, are completely baseless.

"The Air Services Agreement [between Kazakhstan and Mongolia] stipulates the three specific grounds on which Mongolia could possibly revoke the permission of a Kazakh-designated carrier, and none of these apply to Air Astana," the carrier said.

The Kazakh government, through its Ministry of Foreign Affairs and Ministry of Industry and Development, has attempted to engage the Mongolians but without success.

The 3x weekly flights were to have launched on June 2.

Air Astana's flights to Mongolia have also encountered other diplomatic obstacles, from Russia in particular which intends to charge the carrier for transiting its airspace.

Moscow has argued that even though the flight only passes through Russian airspace for a brief 300km stretch, it counts as a Trans Siberian Air Route and should therefore be charged accordingly. Kazakhstan, however, has asked for overflight fees to be waived on the basis of good-neighborliness. The dispute has been a key issue in recent bilateral negotiations between the two former Soviet republics.