'The EU stands with you,' von der Leyen tells Zelensky in Kiev

European Commission President Ursula von der Leyen vowed retribution as she visited Bucha on Friday, as the world recoils from recent reports that Russian troops committed atrocities there as they retreated.

Von der Leyen also promised to stand by Ukrainian President Volodymyr Zelensky and said she would work towards Ukraine's accession to the EU.

The German politician was the first Western leader to travel to the Kiev suburb, where she viewed 20 bodies exhumed from a mass grave there and lit candles in a church for the victims.

"Now the whole world can see the true face of Russia," a uniformed man said as he showed von der Leyen around the site where the bodies lay in black bags. "We knew about it for years. But now the whole world can witness what we had to experience here."

Von der Leyen was initially speechless, despite her familiarity with war zones from her previous post as Germany's defence minister. She then said while it would not heal the wounds, "the whole world is in mourning after everything that happened here."

"We have seen the cruel face of Putin's army, we have seen the ruthlessness and the cold-heartedness with which it has occupied the city," she said.

"It was important to start my visit in Bucha. Because in Bucha our humanity was shattered," von der Leyen tweeted afterwards. "My message to Ukrainian people: Those responsible for the atrocities will be brought to justice. Your fight is our fight."

Ukraine blames Russian troops for the slaying of hundreds of residents. Moscow denies involvement and says images that emerged over the weekend are staged, but has not presented any evidence for this claim.

She later met Zelensky in the Ukrainian capital. "I am here with you today in Kiev to send a clear signal that the European Union stands with you," she said.

Afterwards, Zelensky reiterated his call for further tough sanctions on Moscow, saying "otherwise Russia does not want to understand anyone and anything."

He expressed gratitude for the EU's latest sanctions, but noted that Moscow has taken a great deal from Ukraine. "We can get the land back but not the people," he said.

The bloc's fifth round of sanctions on Russia entered force later in the evening, providing for an embargo on coal, timber and vodka and a full transaction ban on four key Russian banks among other measures.

Von der Leyen was joined by EU foreign policy chief Josep Borrell on her trip, which was intended to send "a strong message of support to Ukrainians," she said.

She wanted to give Ukrainians hope, she said during their train journey to Kiev.

In terms of formal support for Ukraine's membership of the EU, von der Leyen said beforehand that "usually it takes years before the EU Council accepts an application for membership, but Ukraine did that in a week or two and I ask to move forward as soon as possible."

"Our goal is present Ukraine's application to the council this summer."

Borrell announced during the train journey from Poland that the EU's diplomatic representation in the Ukrainian capital would reopen on Friday.

Borrell welcomed the trip as a sign of normality. "It shows that this country is still controlled by the Ukrainians," he said, adding that it was possible to travel to Kiev where a government is capable of welcoming people from abroad.

The head of the EU delegation to Ukraine, Matti Maasikos, was accompanying the top EU officials.

Maasikos is expected to resume his post in the Ukrainian capital with a small team. The EU representation was evacuated from Kiev one day after the start of the war.

Borrell also announced that the EU would provide €7.5 million ($8.15 million) for the investigation Ukraine is conducting into possible war crimes in the Kiev suburb of Bucha and other locations.

Borrell expressed confidence that EU states would soon agree to his proposal to provide Ukraine with an additional €500 million to support the armed forces in their fight against the Russian army.

This would increase the funds available to €1.5 billion.

The officials' visit is the first since the atrocities in Bucha were exposed in recent days.

Austrian Chancellor Karl Nehammer set off on his own trip to Kieve late on Friday. He is expected to meet with Zelensky on Saturday and also travel to Bucha.

In mid-March the prime ministers of Poland, Slovenia and the Czech Republic travelled to Kiev by train. Last week, European Parliament President Roberta Metsola visited the city.

Western leaders are due to gather at the end of May to address the invasion and related defence and energy security issues.