"If there are sanctions related to the energy sector, or further restrictions on Russia's financial sector, we will have to respond,” Medvedev said in an interview with the Vedomosti newspaper, published on Monday.

EU ministers will gather on Monday to discuss new sanctions against Russia and are rumored to be introduced on Tuesday. Russian prime minister promised a strong retaliation if the West slaps Russia with more sanctions.

“We could impose transport restrictions,” Medvedev said, adding, "We believe we have friendly relations with our partners, and foreign airlines of friendly countries are permitted to fly over Russia. However, we’ll have to respond to any restrictions imposed on us."

“If Western carriers have to bypass our airspace, this could drive many struggling airlines into bankruptcy. This is not the way to go. We just hope our partners realize this at some point,” he added.

Flying over Russian airspace saves Western airlines headed to Asia at least 4 hours of flight time, which adds up to about $30,000 per flight.

Lufthansa said it could potentially lose more than €1 billion in three months if it does not use Russian airspace. Lufthansa, along with British Airways and Air France, are the largest EU airlines. US airlines currently don't operate over Siberian airspace.

Western powers and the Kiev government accuse Moscow of having a hand in the crisis in eastern Ukraine, which erupted when Kiev launched military operations in April to silence pro-Russia protests. Russia denies the accusation.

RA/NJF