The US and Britain announced new sanctions against Russia Wednesday after Ukraine said hundreds of civilians were found dead around its capital, as Kyiv warned residents in the east of the country to get out "now" ahead of a feared assault.
The White House unveiled measures targeting Russia's top public and private banks and two daughters of President Vladimir Putin, while Britain sanctioned two banks -- and vowed to eliminate all Russian oil and gas imports by year-end.
Their actions followed an international outcry after Ukraine said its forces found hundreds of civilians dead around the capital Kyiv, including the town of Bucha, after Russian troops withdrew.
In a video address to the UN Security Council on Tuesday, Ukrainian leader Volodymyr Zelensky showed harrowing images of corpses -- including of children -- that he said were victims of Russian atrocities.
The Kremlin denies responsibility and on Wednesday, Putin accused Ukrainian authorities of being behind "crude and cynical provocations" in Bucha, in a call with Hungary's prime minister, the Kremlin said.
The Russian withdrawal from areas around Kyiv and the north is part of a shift in focus towards Ukraine's southeast, in a bid to create a land bridge between occupied Crimea and Moscow-backed separatist statelets in the region of Donbas.
Ukraine Deputy Prime Minister Iryna Vereshchuk on Wednesday warned residents in the eastern Kharkiv, Lugansk and Donetsk regions to leave immediately due a feared Russian attack.
"It has to be done now because later people will be under fire and face the threat of death," she wrote on Telegram.
NATO chief Jens Stoltenberg said there was no sign Putin had dropped "his ambition to control the whole of Ukraine".
"We have to be realistic and realize that this may last for a long time, for many months, for even years," he said ahead of a meeting with NATO foreign ministers.
'Slashed their throats'
Zelensky called for Russia's exclusion from the UN Security Council, where it is one of five members with veto power, and made an impassioned plea for action in response to the civilian killings.
"They cut off limbs... slashed their throats. Women were raped and killed in front of their children," he said, after earlier comparing Russia's assault to the 1937 Nazi bombing of the town of Guernica.
The US and Britain have also pressed to have Russia excluded from the UN Human Rights Council, with a vote in the General Assembly scheduled for Thursday.
At his weekly audience at the Vatican, Pope Francis deplored the "powerlessness of international organizations" before what he called "ever more horrendous cruelties", before kissing a flag brought from Bucha.
Thousands of people have been killed and more than 11 million displaced as refugees or within Ukraine since Russia invaded, sparking Europe's largest refugee crisis since World War II.
Western powers have already pummeled Russia with debilitating economic sanctions, which forced Moscow Wednesday to make foreign debt payments on dollar-denominated bonds in rubles, raising the prospect of a potential default.
Washington's new sanctions targeted Maria Vorontsova and Katerina Tikhonova, two adult daughters of Putin, plus the wife and daughter of Foreign Minister Sergei Lavrov and members of the Russia's Security Council.
The White House also declared "full blocking" sanctions on Russia's largest public and private financial institutions, Sberbank and Alfa Bank, and said all new US investment in Russia was now prohibited.
Britain meanwhile froze the overseas assets of Sberbank -- Russia's largest bank -- and Credit Bank of Moscow.
Prime Minister Boris Johnson had earlier said what happened in Bucha "doesn't look far short of genocide to me".
EU 'indecisiveness'
The EU is also poised to implement a fifth round of sanctions cutting off Russian coal imports -- and European Council chief Charles Michel said that "sooner or later", it must also impose oil and gas sanctions.
Condemning "war crimes" in Russia, he said: "There must be, and there will be, severe consequences for all those responsible."
But addressing the Irish parliament Wednesday, Zelensky condemned the "indecisiveness" on the part of European nations dependent on Russian energy.
He called for the total exclusion of Russian banks from Western finance.
In other moves to isolate Moscow, EU countries including Germany, France, Italy and Spain have expelled more than 200 Russian diplomats and staff between them this week.
The Kremlin called the mass expulsions a "short-sighted move" that would complicate efforts to negotiate an end to the hostilities.
Peace talks between the sides have so far gone nowhere, though Moscow says it is "ready" to continue.
Putin also warned of "reprisals" for recent European measures targeting Russian gas giant Gazprom -- and said Moscow would "monitor" its food exports to "hostile" nations, raising the specter of shortages and price spikes.
Cluster bombs flying
Satellite photos taken while Bucha was still under Moscow's control show what appear to be bodies lying in streets where the dead were later found by Ukrainian forces and seen by journalists.
And multiple Bucha residents told AFP they had seen Russian soldiers killing civilians.
"Right in front of my eyes, they fired on a man who was going to get food at the supermarket," said 43-year-old Olena, who declined to give her family name.
During a grim cleanup, the remains of partially burned bodies in black bags were lifted into a van, with officials telling journalists "dozens of bodies" remained in apartments and in nearby woods.
European Commission chief Ursula von der Leyen, who will visit Kyiv this week, has offered the bloc's assistance in documenting proof of war crimes.
Scenes of devastation have met those venturing into other areas from which Russian forces have withdrawn.
In the northern city of Chernigiv, which was besieged from the early days of the invasion, a charred children's hospital, full of bullet and shrapnel holes, served as a shelter.
"Cluster bombs were flying, we have traces of these bombs," said 51-year-old Olena Makoviy. "The injured were brought to the children's hospital, both adults and children."
City officials estimate around 350 civilians have been killed in Chernigiv, with fellow residents digging mass graves to bury them.
"It was very scary here from the first days of the war," said Makoviy. "They brought guys, handsome, young, but no longer alive,"
