LONDON – British Prime Minister Keir Starmer is convening a second meeting of global leaders Saturday to discuss the developments regarding the war in Ukraine, following another frantic week of diplomacy aimed at getting Russia to back a 30-day ceasefire.

Unlike the first summit on March 2, the meeting of what Starmer has termed the “coalition of the willing” will be conducted virtually. The call is expected to delve into how countries can help Ukraine militarily and financially as well as gauging support for any future possible peacekeeping mission.

“If Russia finally comes to the table, then we must be ready to monitor a ceasefire to ensure it is a serious, and enduring peace,” Starmer is set to tell leaders, in remarks released by his office ahead of the meeting. “If they don’t, then we need to strain every sinew to ramp up economic pressure on Russia to secure an end to this war.”

Around 25 countries are expected to be involved in the call, including European partners, and Ukraine. Leaders from Australia, Canada, New Zealand and Ukraine, as well as officials from NATO and the European Union’s executive, are also set to take part.

Like last time, there will be no representative from the United States, which has shifted its approach on the war since the return of President Donald Trump to the White House. The change of approach relative to that taken by Trump’s predecessor, Joe Biden, became particularly notable after Trump clashed with Ukrainian President Volodymyr Zelenskyy on Feb. 28 in the Oval Office.

Saturday’s meeting takes place in the wake of a U.S. proposal for a 30-day ceasefire in Ukraine, which Zelenskyy has backed.

Russian President Vladimir Putin has indicated that he supported a truce in principle but has set out a host of details that need to be clarified before agreeing to a ceasefire. U.S. Secretary of State Marco Rubio has voiced “cautious optimism” about the possibility of Putin, who met with U.S. envoy Steve Witkoff, on Thursday, backing a ceasefire.

Starmer appears to be less optimistic, and is set to tell leaders that concrete commitments are required now as Putin plays “pointless games” with Trump’s peace plan.

“Putin is trying to delay, saying there must be a painstaking study before a ceasefire can take place. But the world needs to see action, not a study, or empty words and pointless conditions,” Starmer said. “The Kremlin’s complete disregard for President Trump’s ceasefire proposal only serves to demonstrate that Putin is not serious about peace.”

Starmer has taken the lead, along with French President Emmanuel Macron, in assembling the “coalition of the willing” in part to persuade Trump to maintain support for Kyiv. One outcome has already been a growing acceptance from European countries in particular that they need to do more secure their own security, including by increasing their defense spending.

Macron said he had spoken Friday with both Zelenskyy and Starmer about progress at the U.S.-Ukraine talks earlier this week in Jeddah, Saudi Arabia, which led to Trump resuming military aid and intelligence sharing with Kyiv.

Saturday’s meeting, he said, will “continue to work on reinforcing the support for Ukraine and toward a solid and lasting peace.”

Ukraine, under severe military pressure on parts of the front line three years after Russia’s full-scale invasion, has already endorsed the truce proposal. Russia’s army has gained battlefield momentum, and analysts say Putin likely will be reluctant to rush into a ceasefire while he feels he has an advantage.

“My message to the Kremlin could not be clearer: stop the barbaric attacks on Ukraine, once and for all, and agree to a ceasefire now,” Starmer said.