Reuters-Russia warned on Thursday (April 1) that a serious escalation in the conflict in Donbass could "destroy" Ukraine as NATO voiced concern over what it said was a big Russian military build-up near eastern Ukraine.
Unverified social media footage has suggested Russia has been moving large quantities of tanks, armored personnel carriers and other equipment to regions that border Ukraine as well as to Crimea.
Moscow and Kyiv have long accused each other of failing to implement a peace deal over Donbass. Relations are further strained by the fate of the Nord Stream 2 gas pipeline to Germany, which Kyiv and Washington want to halt, and by a crackdown in Ukraine on a prominent businessman close to Russia.
NATO said it was concerned about the Russian military build-up as NATO ambassadors met to discuss a recent spike in violence in the eastern Donbass region, where Ukrainian troops have battled Russian-backed forces in a conflict Kyiv estimates has killed 14,000 people since 2014.
Ukrainian Foreign Minister Dmytro Kuleba accused Russia of a "systemic aggravation" of the security situation in Donbass and Crimea.
Kremlin spokesman Dmitry Peskov played down the build-up, saying "this should not bother anyone and it poses no threat to anyone." Russia was taking measures to ensure the security of its own borders, he said.
Russian Foreign Minister Sergei Lavrov said that most of Ukraine's military appeared to understand the danger of a "hot conflict" in Donbass.
"I very much hope that they will not be 'incited' by politicians, who in turn will be 'incited' by the West, led by the United States," said Lavrov.
"Russian President Putin said (this) not long ago, but this statement is still relevant today, that those who would try to start a new war in Donbass - will destroy Ukraine."
Ukraine, Western countries and NATO accuse Russia of sending troops and heavy weapons to prop up its proxies in Donbass who seized a swathe of eastern Ukraine in 2014.
Russia says it only provides political and humanitarian support to fighters in what it casts as an internal conflict.
