Moscow - Russia has closed its airspace for Slovenian, Latvian, Lithuanian and Estonian planes, a retaliatory measure after these countries banned Russian aircraft from their airspace due to Russia's invasion of Ukraine.

"Due to unfriendly moves by aviation authorities of Latvia, Lithuania, Slovenia and Estonia, restrictions will be introduced for air carriers of the above-mentioned states and/or airlines registered there," Russia's Federal Agency for Air Transport said on Saturday.

The restrictions apply to flights to destinations on the Russian territory, including transit flights via the Russian Federation's airspace, according to Russia press agency TASS.

After the collapse of Adria Airways, Slovenia no longer has a national airline, though there are some small providers of air services registered in the country.

Russian carrier Aeroflot operated flights between Ljubljana and Moscow, but the route has now been suspended, according to the website of the Ljubljana Jože Pučnik Airport.