Artillery pounded key cities in Ukraine on Wednesday, as its president urged the West to act decisively in imposing new and tougher sanctions being readied against Russia in response to civilian killings widely condemned as war crimes.
Western sanctions over Russia's invasion gained new impetus this week when dead civilians shot at close range were found in the town of Bucha after it was retaken from Russian forces.
As Pope Francis described the killings there as a "massacre", the head of the European Commission signaled further sanctions - including examining a ban on energy imports - on top of ones unveiled by the bloc on Tuesday. Washington is in turn due to announce new sanctions on Wednesday.
Ukrainian President Volodymyr Zelenskiy said the West needed to act decisively in taking "more rigid" steps.
"When we are hearing new rhetoric about sanctions... I can't tolerate any indecisiveness after everything that Russian troops have done," he told Irish lawmakers by videolink.
Ukrainian officials say between 150 and 300 bodies might be in a mass grave by a church in Bucha, north of the capital Kyiv, where satellite images taken weeks ago show bodies of civilians on a street, a private US company said.
Moscow, which refers to the conflict as a "special military operation" designed to demilitarize Ukraine, denied targeting civilians there and called the evidence presented a forgery staged by the West to discredit it.
To the south, the besieged southern port of Mariupol has been under bombardment throughout most of the invasion that began on Feb. 24, trapping tens of thousands of residents without food, water or power.
"The humanitarian situation in the city is worsening," British military intelligence said on Wednesday, while Ukraine's Deputy Prime Minister Iryna Vereshchuk said people trying to flee would have to use their own vehicles..
Reuters could not immediately verify the British report.
Vereshchuk said authorities would try to evacuate civilians trapped elsewhere through 11 humanitarian corridors.
Energy sanctions push?
Ukraine's foreign minister said that while he welcomed the latest set of EU sanctions only an embargo on Russian gas and oil and cutting off all Russian banks from the global financial system could "stop" President Vladimir Putin.
"I will take a gas/oil embargo and de-SWIFTing of all Russian banks to stop Putin. Difficult times require difficult decisions," Dmytro Kuleba said on Twitter.
Russian forces last week pulled back from positions outside Kyiv and shifted the focus of their assault away from the capital, and Ukraine's general staff said the northeastern city of Kharkiv, the country's second-largest, also remained under attack.
Authorities in the eastern region of Luhansk on Wednesday urged residents to get out "while it is safe" from an area that Ukraine also expects to be the target of a new offensive.
Speaking a day after the European Union announced new sanctions, including a ban on Russian coal imports and denying Russian ships access to EU ports, the head of the EU executive, Ursula von der Leyen, said there was more to come.
"These sanctions will not be our last sanctions," she told European Parliament on Wednesday. "Now we have to look into oil and revenues Russia gets from fossil fuels."
Von der Leyen's remarks signaled the bloc's strengthening resolve to take the step that Kyiv says is vital to securing a deal to end the war. But German Finance Minster Christian Lindner said in a newspaper interview, Europe's biggest economy which relies on Russian gas for much of its energy needs, was just not ready for an immediate ban.
The White House said earlier that new sanctions, coordinated between Washington, the Group of Seven advanced economies and the EU, will target Russian banks and officials and ban new investment in Russia.