Russia has moved an unknown number of Sukhoi Su-25SM fighter jets into Belarus, days before a planned military manoeuvre in the country that borders Ukraine.
The aircraft were sent 7,000 kilometres from the Primorye region on the Sea of Japan to military airfields in the Brest region in western Belarus, the Defence Ministry in Moscow said on Saturday, without indicating an exact figure.
Moscow is planning to hold a military manoeuvre in Belarus, its close ally, from February 10 to 20.
Western allies fear that Russia may be planning an incursion into Ukrainian territory. The Kremlin vehemently denies this and in return accuses NATO of stoking tensions in the region.
Among the various possibilities suspected by Western intelligence sources would be for Russia to enter through Ukraine's Donbas region, which is controlled by pro-Russian separatists. Another is for Russia to invade from Belarus, which is close to the Ukrainian capital Kiev.
More NATO troops
NATO countries have been moving more ships, aircraft and troops into the Baltics and Eastern Europe in recent weeks.
The alliance has accused Russia of amassing some 30,000 combat troops in Belarus, including aircraft, nuclear-tipped Iskander missiles, S-400 air defence systems, and special units of the GRU military intelligence agency. That augments the 100,000 Russian troops already near Ukraine's border.
Russian Defence Minister Sergei Shoigu has indicated that fewer than 13,000 Russian soldiers, 300 tanks, 500 armoured vehicles and 3,500 paratroopers will be involved in the exercises in Belarus.