Mr Zelensky will address the House of Commons at 5pm by video link after Speaker Lindsay Hoyle approved a request for the “historic address” from the leader who, according to reports, is at risk of assassination by pro-Russian groups in Kyiv.
He gave an address to the European Parliament last week and imparted a virtual message to the US Senate on Saturday, with the embattled leader expected to renew messages from those speeches to MPs, including pushing for the West to install a no-fly zone over Ukraine and for more arms to be delivered.
Mr Johnson will host leaders of the Visegrad Four of central European nations – the Czech Republic, Hungary, Poland and Slovakia – to discuss the conflict today.
The Prime Minister has consistently ruled out the UK policing Ukrainian skies, arguing it would mean shooting down Russian planes.
The Ministry of Defence (MoD) has said Russia is “likely” ramping up claims Ukraine is developing nuclear or biological weapons as “retrospective justification” for its invasion.
“Since the end of February there has been a notable intensification of Russian accusations that Ukraine is developing nuclear or biological weapons,” a MoD statement said.
“These narratives are long standing but are currently likely being amplified as part of retrospective justification for Russia’s invasion of Ukraine.”
On Monday evening, Mr Johnson spoke with US President Joe Biden, French President Emmanuel Macron and German Chancellor Olaf Scholz, with the four leaders vowing to “continue to apply pressure on Russia to isolate Putin diplomatically and economically”.
A No 10 spokeswoman said: “The Prime Minister stressed that our goal must be ensuring Putin’s failure in this act of aggression against Ukraine.”
The Foreign Secretary met with the Ukrainian ambassador to the UK, Vadym Prystaiko, on the same evening.
Liz Truss tweeted afterwards that the UK is working to “cripple” Russia’s war effort and to rally the international community.
The diplomatic efforts on the international stage comes as the UK Government faced domestic pressure to speed-up its efforts to grant safety to fleeing Ukrainians, with Labour criticising the process for being “painfully slow”.
The Home Office on Friday confirmed that 8,900 applications for refugees to come to the UK via the Ukraine Family Scheme had been submitted since Friday, but that only 300 visas had been issued.
Shadow home secretary Yvette Cooper tweeted: “That’s shockingly low and painfully slow. Just 250 since yesterday.
“At this rate it would be weeks before many families reunite. Urgent action needed.”
Defence Secretary Ben Wallace said he would update MPs on Wednesday on the support being offered by the UK to the Ukrainian forces.
He told Sky News: “We started off, obviously, with 2,000 Nlaws – light anti-tank weapons.
“We’ve changed and increased both the Nlaws and others, and I will make a statement tomorrow, I think, in Parliament to give the details.
“Britain is stepping up and doing that, we are supporting the co-ordination of delivery throughout Ukraine.”
The UK was “in a good place to make sure they get better defence and more defence”.