Russian troops are constantly hearing those fighting for Ukraine on the front lines speaking foreign languages, and the Kremlin has vowed that such fighters will be"destroyed," Reuters reported.

Russia has long claimed that NATO military personnel are present in Ukraine and that its eavesdropping services have picked up English and French spoken repeatedly on the front lines.

The US-led NATO military alliance says it supports Ukraine but has not deployed troops there.

American media reports that American and leading European intelligence agencies have a significant presence in Ukraine, Reuters recalls.

"Our military hears foreign languages, they constantly hear foreign languages at the front," Kremlin spokesman Dmitry Peskov told reporters when asked about allegations that France was preparing to deploy troops in Ukraine."So these foreigners are there, we are destroying them. Our military will continue to do their job."

Peskov noted that Russia cannot assess the peace talks with Ukraine because Kiev has suspended them and is unwilling to answer the questions asked by Russia.

The Kremlin takes note of statements by US President Donald Trump calling on other countries to stop buying Russian oil, but Moscow's partners will make their own decisions on whether to continue buying its energy products, Peskov also said.