Boris Johnson will tell fellow leaders that “the people of Ukraine will be our judge” if the west fails to defeat Vladimir Putin.
The Prime Minister will say “the world is watching” as he unveils a six-point plan of action to help preserve Ukraine’s independence in the face of mounting Russian aggression.
Johnson will this week meet with leaders from Canada, the Netherlands and central Europe as he seeks to bolster the global anti-Putin coalition.
He will tell them that Ukraine must receive more military and humanitarian support if Russia is to be beaten.
“Putin must fail and must be seen to fail in this act of aggression,” the PM will say.
“It is not enough to express our support for the rules-based international order – we must defend it against a sustained attempt to rewrite the rules by military force.
“The world is watching. It is not future historians but the people of Ukraine who will be our judge.”
Johnson will unveil his his six-point plan in a New York Times article on Sunday.
He is calling for an international humanitarian coalition to help Ukraine and for the maximum economic pressure to be placed on Putin’s regime.
The ”creeping normalisation of what Russia is doing in Ukraine” must be prevented, according to the PM, while diplomacy aimed at the de-escalation of Russian aggression must be stepped up and fully involve the Ukrainian government.
Finally, Downing Street said Johnson wants to see “a rapid campaign to strengthen security and resilience across the Euro-Atlantic area.
Canadian prime minister Justin Trudeau and Dutch prime minister Mark Rutte will meet with the PM in Downing Street on Monday to discuss the Ukraine crisis.
It follows talks on Friday with French president Emmanuel Macron and the leaders of Turkey and Serbia.
On Tuesday, Johnson he will host leaders of the ‘V4’ group of central European nations – the Czech Republic, Hungary, Poland and Slovakia - which are already experiencing first-hand the humanitarian crisis caused by Russia’s invasion of Ukraine.
The government has said that Ukrainian refugees with family members in the UK will be able to live here for up to three years, a move which ministers claim could potentially benefit 200,000 people fleeing the war.