PARIS — On a day of commemoration of the end of World War II in Europe, the war in Ukraine was marked by posturing and signaling on Sunday, as each side ramped up its rhetoric and resolve.
Leaders of the world’s wealthiest democracies vowed to end their dependence on Russian energy and ensure that Russia does not triumph in its “unprovoked, unjustifiable and illegal aggression,” as President Vladimir V. Putin pursued his indiscriminate bombardment of eastern Ukraine and orchestrated celebrations for Russia’s Victory Day holiday on Monday.
A statement by the Group of 7 major industrialized nations said that on a day when Europe recalled the devastation of World War II and its millions of victims, including those from the Soviet Union, Mr. Putin’s “actions bring shame on Russia and the historic sacrifices of its people.”
The leaders, signaling to Mr. Putin that their unrelenting support of Ukraine would only grow, said, “We remain united in our resolve that President Putin must not win his war against Ukraine.” The memory of all those who fought for freedom in World War II, the statement said, obliged them “to continue fighting for it today.”
The tone was firm, with no mention of any potential diplomacy or cease-fire.
In Moscow, as fighter jets streaked across the sky and nuclear weapons were put on display in preparation for Victory Day, Mr. Putin appeared to signal back to Western leaders that he was determined to double down on the war until he could conjure something that might be claimed as victory.
There was fresh evidence of that on Sunday, as rescuers picked through the rubble in Bilohorivka, a village in the Luhansk region of eastern Ukraine where a Russian bomb had flattened a school building the day before, killing people sheltering there, local authorities said.
“Most likely, all 60 people who remain under the rubble are now dead,” Gov. Serhiy Haidai wrote on the Telegram messaging app. But it was unclear how many people were in fact in the school and that toll may prove inflated. If confirmed, it would be one of the deadliest single Russian attacks since the war began in February.
Despite the World War II commemorations in most of Europe on Sunday and in Russia on Monday, a painful reminder of the tens of millions of people killed, there was no indication that the war in Ukraine was anywhere near ending. If anything, all signals pointed in the opposite direction. Russian attacks on Ukrainian towns and villages met a crescendo of Western rhetoric, accompanied by the constant danger of escalation.
Mr. Putin, whose steady militarization of Russian society in recent years has turned the May 9 celebration of the Soviet defeat of the Nazis into an annual apotheosis of a resurgent nation’s might, is expected to portray a war of repeated setbacks in Ukraine as a successful drive to “de-Nazify” a neighboring nation whose very existence he denies.
His much-anticipated speech may go further, possibly signaling that whatever conquest in Ukraine there has been up to now will become permanent through annexation. Russia annexed Crimea in 2014 and began stirring military conflict in the eastern Donbas region.
In Mariupol, the Ukrainian port city now in ruins after sustained Russian assault, and a place Mr. Putin wants to showcase as evidence of his “victory,” the city’s last Ukrainian defenders vowed to fight on. Russian forces were cleaning the streets on Sunday in possible preparation for a celebratory parade on Monday.
Across eastern Ukraine, Russia appeared intent on making its occupation permanent through Russian flags, Russian-language signs and the introduction of the ruble. The Group of 7 leaders said any attempts “to replace democratically elected Ukrainian local authorities with illegitimate ones” would not be recognized.
Visits to the region by the first lady, Jill Biden, who crossed into western Ukraine to meet Ukraine’s first lady, Olena Zelenska, in an unannounced visit to Uzhhorod, and by Justin Trudeau, the Canadian prime minister, who appeared unexpectedly in a war-scarred suburb of Kyiv, were clearly intended to drive home a message of unwavering Western commitment.
Senior American diplomats returned to the U.S. Embassy in Kyiv for the first time since the war began.
President Volodymyr Zelensky of Ukraine released a black-and-white video address on Sunday marking the Allied victory in 1945. Standing in front of a destroyed apartment block in a Kyiv suburb hit hard by Russian troops before their withdrawal from the region around the capital, he said, “We pay our respect to everyone who defended the planet against Nazism during World War II.”
Mr. Putin has portrayed Mr. Zelensky, who is Jewish, as the leader of a nation threatening Russia with revived Nazism. His aim has been to instill the spirit of the Great Patriotic War, as World War II is known in Russia, among Russian troops, but to little apparent avail.
In the vast Azovstal steel mill that is the last remaining part of Mariupol not under Russian control, Ukrainian troops again rejected Russian deadlines to surrender. In a virtual news conference, Lt. Illya Samoilenko, an officer in a Ukrainian National Guard battalion known as the Azov regiment, said: “We are basically dead men. Most of us know this. That is why we fight.”
Capt. Sviatoslav Palamar, a deputy commander of the regiment, said, “We don’t have much time, we are under constant shelling,” with attacks from Russian tanks, artillery, airplanes and snipers.
The remaining civilians in the steel plant were evacuated on Saturday. Local officials estimate the death toll in the city at over 20,000.
If the United States and its allies have refused to commit military forces for fear of sparking World War III, they have moved to support Ukraine in every other way, their determination mounting and their actions expanding with each Russian atrocity.
The Group of 7 statement included a series of economic, military and judicial steps, with the apparent aim of bringing the Russian economy to its knees and increasing the pressure on Mr. Putin to turn back from a war of choice that has turned him into a pariah and threatens much of his country’s progress over the past two decades.
“We commit to phase out our dependency on Russian energy, including by phasing out or banning the import of Russian oil,” the statement said. It added, without being specific, that this would be done in a “timely and orderly fashion.” Alternative sources, they added, would be found to ensure “affordable prices for consumers.”
Russia-Ukraine War: Key Developments
A show of support. In a high-profile display of solidarity with Ukraine on the eve of a key Russian military holiday, Jill Biden, the first lady, made an unannounced visit to western Ukraine. Canada’s leader, Justin Trudeau, also made an unannounced trip to the Kyiv suburb of Irpin.
It was unclear how this commitment from the Group of 7 went beyond existing undertakings, if at all.
The 27-nation European Union has already committed to a complete import ban on all Russian oil, with most countries phasing out Russian crude oil within six months and refined oil by the end of the year. The European Union is too dependent on Russian gas to consider banning it in the short term.
The war has already driven up gasoline prices across much of Europe in a generally inflationary climate. If the war drags on for a long time, it is likely that support for the West’s commitment to Ukraine may waver among consumers paying the cost at the pump or in their utility bills.
The statement of the Group of 7, meeting remotely, said the seven nations — the United States, France, Britain, Japan, Germany, Canada and Italy — had already provided or pledged $24 billion to Ukraine for 2022. “In the coming weeks, we will step up our collective short-term financial support,” they said.
“We will continue to take action against Russian banks connected to the global economy and systematically critical to the Russian financial system,” they added. More generally, they would “take measures to prohibit or otherwise prevent the provision of key services on which Russia depends.”
Military and defense assistance would continue to ensure that “Ukraine can defend itself now and deter future acts of aggression.”
The leaders said they would “spare no effort to hold President Putin” and his accomplices “accountable for their actions in accordance with international law.”
The charges of illegality leveled at Mr. Putin for the invasion of a sovereign country are certain to anger the Russian president. The NATO bombing of Belgrade in 1999 during the Kosovo War, the United States invasion of Iraq in 2003 and Western support for the independence of Kosovo in 2008 have given him a healthy distrust of American invocations of the United Nations Charter and international law.
War raged in Ukraine’s east on Sunday, with a Ukrainian counteroffensive near Kharkiv, the country’s second largest city, gaining ground in the northeast. However, the Ukrainian army withdrew from the city of Popasna after two months of fierce fighting.
In general, the planned Russian offensive in the east of the country, like the rest of Mr. Putin’s war, has gone less well than planned. Mr. Putin’s broad aim, at least for the time being, seems to be to connect Crimea through Mariupol to other occupied areas in eastern Ukraine, and to Russia itself, forming a cohesive and strategic swath of territory.
William J. Burns, the C.I.A. director and former U.S. ambassador to Russia, said the current phase of the war was at least as dangerous as Russia’s initial attempt to attack the capital and topple the Ukrainian government.
Speaking on Saturday in Washington, he said Mr. Putin was “in a frame of mind that he thinks he cannot afford to lose,” and was convinced that “doubling down still will enable him to make progress.”
In the 77 years since the end of World War II, the possibility of a broad conflagration in Europe has seldom, if ever, appeared more plausible.
Reporting was contributed by Emma Bubola in London; Eduardo Medina in New York; Marc Santora in Krakow, Poland; Maria Varenikova in Kyiv, Ukraine; Katie Rogers in Uzhhorod, Ukraine; Julian E. Barnes and Michael Crowley in Washington; and Cassandra Vinograd in London.