Leaders of the world's richest democracies say they will not back down from supporting Ukraine, in a warning to Russian President Vladimir Putin as he claimed to have taken the eastern city of Bakhmut.
The Group of Seven (G7) summit in the Japanese city of Hiroshima was electrified this weekend by the arrival of Ukrainian President Volodymyr Zelenskiy, who arrived on a French government plane to canvass for greater support against Russia's invasion.
Zelenskiy told reporters on the sidelines of the summit that the battered eastern city of Bakhmut, the focus of fighting in recent months, was destroyed.
"It is tragedy," Zelenskiy said. "There is nothing on this place" - what remained was "a lot of dead Russians".
There was confusion over whether he had been asked if the city was still in Kyiv's hands or Russian forces had taken Bakhmut, but a Zelenskiy spokesperson said the comments were a denial the city had fallen.
Zelenskiy later made his way to Hiroshima's peace memorial, where he laid flowers at the cenotaph to victims of the world's first nuclear bombing. He is also expected to give a speech in a nation that has seen an outpouring of support for Kyiv's fight.
During the final day of the three-day G7 summit, US President Joe Biden announced a $US375 million ($A564 million) package of military aid, including artillery and armoured vehicles, for Ukraine.
He told Zelenskiy the United States was doing all it could to strengthen Ukraine's defence against Russia.
"Together with the entire G7 we have Ukraine's back and I promise we're not going anywhere," Biden said.
Putin hailed what he said was a victory for his forces, describing it as the "liberation" of Bakhmut in a statement on the Kremlin's website.
The assault on the largely levelled city was led by troops from the Wagner Group of mercenaries, whose leader Yevgeny Prigozhin said his troops had finally pushed the Ukrainians out of the last built-up area inside the city.
Other leaders of the G7 - the United States, Japan, Germany, Britain, France, Italy and Canada - echoed Biden's sentiments.
Canadian Prime Minister Justin Trudeau promised that his country would support Ukraine for as long and as much as necessary.
Biden told G7 leaders Washington supports joint allied training programs for Ukrainian pilots on F-16 warplanes, although Kyiv has not won commitments for delivery of the fighter jets.
British Prime Minister Rishi Sunak said training would start this summer and Ukraine would get the air force it needed for the future.
While determination to help Ukraine repel Russia's invasion was a key message from the G7 summit, the other was distrust of China as a trading partner.
Biden met with the leaders of Japan and South Korea on Sunday to discuss military interoperability and the economic coercion they face from China, a US official said.
A day earlier, the G7 leaders outlined a shared approach towards China, looking to "de-risk, not decouple" economic engagement with a country regarded as the factory of the world.
In a statement the G7 also reaffirmed the importance of peace and stability across the Taiwan Strait, where Chinese military exercises have raised concerns over the security of Taiwan, the democratic, self-governed island that China regards as part of its territory.
China's foreign ministry issued a complaint to Japan expressing firm opposition to the G7 statement, saying it disregarded China's concerns, had attacked it and interfered in its internal affairs, including Taiwan.
