Boris Johnson will telephone Russian President Vladimir Putin and visit Eastern Europe in the coming days as the UK steps up its diplomatic efforts to resolve the Ukraine border crisis.
No 10 said the PM would repeat the need for Russia to “engage diplomatically” when he spoke to Mr Putin this week.
He would “reiterate the need for Russia to step back”, No 10 added.
Mr Johnson has said the UK could deploy troops to protect Nato allies if Russia invaded Ukraine.
Russia – which has denied it plans to invade Ukraine – has placed about 100,00 troops, tanks, artillery and missiles near Ukraine’s border.
It is the first time since World War Two that Russia has moved troops from the east of the country to the Ukraine border.
As well as Mr Johnson’s visit to the region, Foreign Secretary Liz Truss will visit Moscow in the next two weeks, the Russian Embassy in the UK said.