Russia has deployed MiG-31K fighter jets with hypersonic Kinzhal missiles and long-range Tupolev Tu-22M strategic bombers to its air base in Syria for naval exercises, Interfax news agency reported on Tuesday, citing the defence ministry.

The aircraft dispatched to Russia's Hmeimim air base will take part in exercises in the eastern Mediterranean, part of a surge of Russian military activity amid a standoff with the West over Ukraine and security in Europe.

Moscow announced on January 20 that its navy would stage an array of exercises involving all its fleets from the Pacific to the Atlantic, drawing on 10,000 servicemen, 140 warships and dozens of planes.

Syrian President Bashar al-Assad's Damascus has been a staunch ally of Moscow since Russia launched an air strike campaign in Syria in 2015. Apart from the Hmeimim air base, Russia also controls the Tartus naval facility.

Russia sent fighter jets with Kinzhal missiles for the first time last year after expanding the runway at the base to handle such aircraft, said Rob Lee, a military analyst at the US-based Foreign Policy Research Institute.

He said the deployments pointed to Russia's growing military presence in the Middle East and its ability to operate in different regions and to project power.

Russian media have said the Kinzhal hypersonic missile can hit targets up to 2,000 km (1,243 miles) away. It is one of several strategic weapons unveiled by Russian President Vladimir Putin in March 2018.