The Prime Minister will speak to Vladimir Putin next week and visit the Ukraine region in a bid to stop a Russia invasion.
It comes as Russia is reportedly sending army medical units to the Ukrainian front, according to Western defence officials.
Tonight, a Downing Street spokeswoman said: " The Prime Minister is determined to accelerate diplomatic efforts and ramp up deterrence to avoid bloodshed in Europe.
“He will reiterate the need for Russia to step back and engage diplomatically when he speaks to President Putin this week."
Boris Johnson is also to visit the Ukraine region in the coming days after the Ministry of Defence set out a range of options to mitigate against growing Russian aggression in the region, including fresh deployments and bolstering of NATO’s defences.
Separately, it is known Russia recently held a major medical training exercise involving army medics and 1,200 military police officers in its Western military district which borders Ukraine.
This involved drills on troops with mock “shrapnel and bullet wounds”.
Russian army medics and police rehearsed evacuating the wounded from battlefields - and "operating on severely wounded" men, said a military statement.
Military police officers under the supervision of military doctors performed resuscitation procedures, both on simulated sick servicemen and on special mannequins, stated an Interfax report.
It read: “Military police officers in conditions of simulated combat performed evacuation of wounded servicemen, reception and screening at a medical facility, provision of first aid to the injured, as well as performing surgeries to save critically wounded people.”
Until now, the absence of intelligence about medical units has led Ukrainians to believe that an attack by Russia was not an immediate threat.
New videos show yet more heavy military equipment heading both for Belarus and the borders of rebel-held eastern Ukraine.
They also show that trains are still being loaded in the far east of Russia for a 6,000-mile transfer via the Trans-Siberian Railway.
A consignment of tanks and infantry fighting vehicles was spotted at Smolensk, presumably heading to Belarus.
