March 15 (UPI) -- Ukraine's allies have agreed to "put collective pressure" on Russian President Vladimir Putin to agree to a legitimate cease-fire proposal after a virtual summit of Western nations' leaders that didn't include the United States.
Britain's Prime Minister Keir Starmer said "the 'yes but' from Russia is not good enough" regarding the U.S.-proposed cease-fire.
About 25 countries, including European nations, the European Commission, NATO, Canada, Australia and New Zealand, as well as Ukraine's President Volodymyr Zelensky, convened.
The nations are known as the "coalition of the willing."
The United States, under President Donald Trump, has been less supportive of Ukraine, including pausing military support and intelligence temporarily but then resuming them.
The U.S. has allocated nearly $183 billion for the response to Russia's 2022 invasion of Ukraine. That includes approving $33.2 billion for military equipment and services.
Separately, U.S. special envoy Steve Witkoff met with Putin this week about the warf in Ukraine. Trump wrote on Truth Social on Saturday the meetings were "very productive" and that "all signs seem to be, hopefully, very good!"
Starmer and French President Emmanual Macron are leading a coalition that is bigger than two weeks ago when the idea was first floated after a meeting of European leaders and Canada.
"We agreed collective pressure will be put on Russia from all of us who were in the meeting this morning," Starmer said.
He said Trump "has offered Putin the way forward to a lasting peace - now we must make this a reality."
In opening remarks, Starmer said that "if Putin is serious about peace, it's very simple: He has to stop his barbaric attacks on Ukraine and agree to a ceasefire."
He continued, "The world is watching. My feeling is that sooner or later he's going to have to come to the table and engage in serious discussion."
Ukraine earlier this week accepted 30-day cease-fire in Ukraine initiated by the United States but Putin said "we agree with the proposal" but also that the deal "wasn't complete."
Putin is the problem, Zelensky siad.
"A cease-fire could have already happened, but Russia is doing everything to prevent it," he said in a statement on X. "This is Russia's war - more than three years of full-scale fighting and destruction. To stop this, active pressure is needed, not just talks."
Zelensky on Saturday called for an international coalition to intensify pressure on Moscow, not just Europe and the G7 but "all other countries around the world for the sake of peace."
He said the world "must understand that Russia is the only obstacle preventing peace."
The war began three years ago in March and Russia has been advancing in the Kursk border region.
Zelensky said there's no evidence of Putin's claim that Ukrainian soldiers are now surrounded by Russian forces in the region.
The militaries of Ukraine's allies want to keep the peace once a cease-fire is struck in Ukraine.
"We will now move into an operational phase," Starmer said. "Our militaries will meet on Thursday this week here in the United Kingdom to put strong and robust plans in place to swing behind a peace deal and guarantee Ukraine's future security."
He also said: "Overall, we are successfully gathering political and military momentum."
Italian Prime Minister Giorgia Meloni, who joined Saturday's virtual summit, does not envision her nation's participation in a possible military presence in Ukraine, her said office in a statement.
Ukraine's allies agreed to "keep the military aid flowing to Ukraine, and keep tightening restrictions on Russia's economy, to weaken Putin's war machine and bring him to the table."
Zelensky thanked the European Union for a plan to put $163 billion toward strengthening Europe's defense capacity
On Saturday, Russia fired 178 drones and two ballistic missiles at Ukraine overnight, killing at least two people and injuring 44, according to Ukrainian officials. Russia targeted critical infrastructure and residential buildings, damaging seven high-rise buildings and 27 houses.
Russia's Defense Ministry said its air defenses had shot down 126 Ukrainian drones overnight. They didn't say many drones missed.