Russian bombing of a school sheltering civilians claimed 60 lives, Ukraine said on Sunday, as the G7 group of the west's leading economies reaffirmed their solidarity with Kyiv on the eve of Moscow's plans for a major celebration to mark the anniversary of allied victory in World War II.
As intense fighting continues, Ukrainian President Volodymyr Zelensky confirmed the death toll in Saturday's Russian air strike on a school in the eastern village of Bilogorivka.
Russian President Vladimir Putin meanwhile leads commemorations Monday of the Soviet Union's defeat of Nazi Germany.
Putin is expected to flaunt his military might during the symbolically important event. Huge intercontinental ballistic missiles will be towed through Moscow's Red Square, and a planned flyover will feature fighter jets in a "Z" formation showing support for the war.
The Victory Day parade is a longtime tradition in Russia, but Monday's has taken on great prominence as Putin seeks to justify a war that has gone on far longer -- and at far higher cost -- than expected.
Putin has sought to legitimise the invasion by comparing it with the previous struggle against Nazism and the national pride it brought.
"Today, our soldiers, as their ancestors, are fighting side by side to liberate their native land from the Nazi filth with the confidence that, as in 1945, victory will be ours," Putin said.
President Zelensky also marked the end of the 1939-1945 war by comparing Ukraine's battle for national survival to the region's war of resistance against its former Nazi occupiers.
"Decades after World War II, darkness has returned to Ukraine," he said, in a monochrome social media video shot before a bombed-out apartment block.
"Evil has returned, in a different uniform, under different slogans, but for the same purpose."
G7 vows to reduce or ban Russian oil imports
Earlier, in the latest shows of Western support, US First Lady Jill Biden and Canadian Prime Minister Justin Trudeau made unannounced visits to Ukraine, and G7 leaders joined Zelensky on a video call before pledging new support -- including a key vow to ban or phase out imports of Russian oil.
After Zelensky's video conference with G7 leaders, the group -- comprising Britain, Canada, France, Germany, Italy, Japan and the United States -- said in a statement that Putin's "unprovoked war of aggression" had brought "shame on Russia and the historic sacrifices of its people".
The White House said the G7 was "committed to phasing out or banning the import of Russian oil".
EU diplomats will meet again next week to hammer out the details of their latest sanctions package, after a proposed embargo on Russian oil exposed rifts in the bloc.
Separately, the White House said the United States would sanction three major Russian television stations and deny all Russian companies access to US firms' consulting and accounting services.
Trudeau said Putin was responsible for "heinous war crimes" as he visited Irpin, a Kyiv suburb that was the scene of heavy fighting in the early weeks of the conflict.
Separately, First Lady Biden met her Ukrainian counterpart Olena Zelenska at a school sheltering civilians, including children displaced by the conflict, near Ukraine's border with Slovakia.
"I wanted to come on Mother's Day," Jill Biden told reporters, saying she wanted to demonstrate US support for Ukraine.
Civilians leave Mariupol steelworks
Civilians have now been evacuated from Mariupol's Azovstal steelworks, witnesses said.
Their departure leaves a small force of defenders holed up in Azovstal's sprawling network of tunnels and bunkers.
The complex -- the final pocket of Ukrainian resistance in the Black Sea port city -- has taken on symbolic value.
"We, all of the military personnel in the garrison of Mariupol, we have witnessed the war crimes perpetrated by Russia, by the Russian army. We are witnesses," said Ilya Samoilenko, an intelligence officer with the Azov regiment defending the site.
"Surrender is not an option because Russia is not interested in our lives," he said.
Full control of Mariupol would allow Moscow to create a land bridge between the Crimean peninsula, which it annexed in 2014, and eastern regions run by pro-Russian separatists.
UN chief appalled by attack on school
Lugansk region governor Sergiy Gaiday said rescuers in Bilogorivka were searching for survivors in the debris left by the Russian attack on the school there, though the outlook was bleak.
"Bombs fell on the school," he said on Telegram, "and unfortunately it was completely destroyed."
The attack on the school "appalled" UN chief Antonio Guterres, his spokesperson said.
"The secretary-general reiterates that civilians and civilian infrastructure must always be spared in times of war," the spokesperson added.
Rescuers were also looking for survivors in the neighbouring village of Shepilivka after a strike hit a house where 11 people were sheltering in the basement, Gaiday said.
