Boris Johnson is set to tell international leaders “the world is watching” as he urges them to match rhetoric with action over Russia’s invasion with Ukraine.
The Prime Minister will set out a six-point plan on Sunday, which he hopes global counterparts will accept, as Russian leader Vladimir Putin moved the goalposts over the West’s engagement in the conflict in Ukraine.
Mr Johnson said that “it is not future historians but the people of Ukraine who will be our judge” over how the world reacts to Mr Putin’s “hideous, barbarous assault”.
Ahead of a swathe of meetings in coming days, Mr Johnson said: “Putin must fail and must be seen to fail in this act of aggression.
“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.”
Meanwhile, Defence Secretary Ben Wallace warned the Kremlin not to underestimate the West.
In an interview with The Sunday Telegraph, Mr Wallace said allies “must not be afraid of Putin”.
He warned the Russian leader – who he said was “acting irrationally and inflicting horrors on Ukraine” – not to “test” the UK.
“The thing to say to Putin is don’t underestimate us, don’t test us,” he told the newspaper.
“History is littered with authoritarian leaders underestimating the wider West and the United Kingdom. He clearly underestimated the international community.”
He added: “If we stick together and refuse to be intimidated then I believe he will fail.”
Mr Putin warned on Saturday the Kremlin would consider any third-party declaration of a no-fly zone over Ukraine as participation in the conflict.
Mr Putin said Russia would view “any move in this direction” as an intervention that “will pose a threat to our service members”.
“That very second, we will view them as participants of the military conflict, and it would not matter what members they are,” he said.
However, Ukraine has repeatedly said the move is the only way to stop more deaths.
Nato allies have ruled out implementing a no-fly zone over Ukraine amid fears it could prompt an all-out war with nuclear-armed Russia.
But he also said that Western sanctions on Russia were akin to a declaration of war.
Mr Johnson is set to call on his counterparts worldwide to make a “renewed and concerted effort” to tackle Mr Putin, No 10 said.
Already, 141 nations have denounced the Kremlin’s actions at an emergency session of the United Nations Security Council.
Some 38 countries, coordinated by the UK, have also led the largest-ever referral to the International Criminal Court.
But Mr Johnson is set to tell leaders, in an essay in the New York Times on Sunday, that the international community must come together under a six-point plan to keep the pressure on.
The Prime Minister will call on leaders to mobilise an “international humanitarian coalition” for Ukraine and support the country “in its efforts to provide for its own self-defence”.
The economic pressure on the Kremlin should be ratcheted up, Mr Johnson will say, and he will add that leaders must resist the “creeping normalisation” of what Russia is doing in Ukraine.
Mr Johnson will also say that while diplomatic paths to resolving the war must be pursued, this could only be done with the full participation of the “legitimate Government of Ukraine”.
He will add that there also needs to be a “rapid campaign to strengthen security and resilience across the Euro-Atlantic area”.
The PM will hammer home his message when he meets with Canadian Prime Minister Trudeau and Dutch Prime Minister Rutte at Downing Street on Monday.
Then on Tuesday, Mr Johnson will host leaders of the V4 group of central European nations – the Czech Republic, Hungary, Poland and Slovakia.
No 10 said it was these countries that are already facing the humanitarian crisis caused by the invasion, as the number of people fleeing Ukraine reached 1.4 million in just 10 days.
“The world is watching,” Mr Johnson added.
Labour’s shadow foreign secretary David Lammy said the opposition “fully supports the UK playing its part in the united, international effort to provide military, economic, diplomatic and humanitarian assistance to Ukraine alongside our allies and partners in Nato and beyond”.
He said: “We support an immediate ceasefire, and the full and complete withdrawal of Russian forces from Ukraine’s internationally recognised borders.”
Mr Lammy said: “The Putin regime’s illegal invasion of Ukraine is a heinous attack not only on the Ukrainian people, but also on the values of sovereignty, democracy, freedom and the rule of law we all share.”
But he added: “At home, the UK government must move faster and harder to impose sanctions on the oligarchs and politicians linked to the rogue Russian regime.
“It is inexcusable that we have fallen behind the EU and the US on the number of individuals and entities sanctioned. Ministers must move faster, acting against Putin’s cronies in days not months.”