The European Union has proposed to set up a UN-backed specialised court to investigate possible war crimes committed by Russia in Ukraine, and to use frozen Russian assets to rebuild the war-torn country.

European Commission president Ursula von der Leyen said the EU will work with international partners to get “the broadest international support possible” for the tribunal, while continuing to back the work of the International Criminal Court.

Since Russian President Vladimir Putin ordered the invasion of Ukraine on February 24, his military forces have been accused of abuses ranging from killings in the Kyiv suburb of Bucha to deadly attacks on civilian facilities, including the March 16 bombing of a theatre in Mariupol that an Associated Press investigation established was likely to have killed close to 600 people.

Investigations of military crimes committed during the war in Ukraine are under way around Europe, and the Hague-based International Criminal Court has already launched investigations.

Ms von der Leyen said it is estimated that more than 20,000 Ukrainian civilians and more than 100,000 Ukrainian military personnel have been killed since the start of the war.

On Tuesday, Ukrainian first lady Olena Zelenska also urged that Ukraine’s invaders be held account as she addressed legislators in London.

“Victory is not the only thing we need. We need justice,” she said, comparing Russian war crimes to the atrocities committed by Nazi Germany in the Second World War.

She called on the UK to lead efforts to set up a criminal tribunal to prosecute senior Russians over the invasion, similar to the post-war Nuremberg trials of leading Nazis.

Ms von der Leyen said the 27-nation bloc wants to make Russia pay for the destruction it caused in neighbouring Ukraine by using Russian assets frozen under sanctions.

She estimated the damage to Ukraine at 600 billion euro (£518 billion).

“Russia and its oligarchs have to compensate Ukraine for the damage and cover the costs for rebuilding the country,” Ms von der Leyen said. “We have the means to make Russia pay.”

Ms von der Leyen said 300 billion euro (£259 billion) of the Russian central bank reserves has been immobilised, and that 19 billion euro (£16 billion) of Russian oligarchs’ money has been frozen.

“In the short term, we could create with our partners a structure to manage these funds and invest them,” she said.

“We would then use the proceeds for Ukraine, and once the sanctions are lifted, these funds should be used so that Russia pays full compensation for the damages caused to Ukraine.”

The EU said the lifting of the restrictions on Russian assets could be linked to conclusion of a peace deal between Ukraine and Russia that would settle the question of damages reparation.