The EU estimates Ukraine needs an extra €135 billion ($274.1b) to stay afloat over the next two years – with the cash crunch set to start in April.

Zelenskyy said Kyiv needed a decision on its financing by the end of the year and that the move could give it more leverage in talks to end the war.

“Russian assets must be used to defend against Russian aggression and rebuild what was destroyed by Russian attacks. It’s moral. It’s fair. It’s legal,” Zelenskyy said.

German Chancellor Friedrich Merz was among those agreeing strongly as he said there was “no better option”.

But Belgium’s Prime Minister Bart De Wever – who held talks with Zelenskyy on the sidelines – seemed unconvinced so far.

“I have not seen a text that could persuade me to give Belgium’s agreement,” he told Belgian lawmakers before the summit kicked off.

The vast bulk of the assets are held by international deposit organisation Euroclear in Belgium, and the Government fears it could face crippling financial and legal reprisals from Moscow.

EU officials say they have gone out of their way to allay Belgian worries and that multiple layers of protection – including guarantees from other member states – mean the risks are minimal.

“At this stage, the guarantees offered by the Commission remain insufficient,” De Wever said.

Ukraine’s looming cash crunch

In a bid to plug Kyiv’s yawning gap, the Commission has proposed tapping €210b of frozen assets, initially to provide Kyiv €90b over two years.

The unprecedented scheme would see the funds loaned to the EU, which would then loan them on to Ukraine.

Kyiv would then only pay back the “reparations loan” once the Kremlin compensates it for the damage.

In theory, other EU countries could override Belgium and ram the initiative through with a weighted majority, but that would be a nuclear option that few see as likely for now.

De Wever insisted that the EU should go for its alternative plan of raising money itself – but diplomats said that option had been shelved as it needed unanimity and Hungary was firmly against.

Bubbling close to the surface of the EU’s discussion are the US efforts to forge a deal to end the war.

Zelenskyy said Ukrainian and US delegations would hold new talks on Friday and Saturday in the United States.

He said he wanted Washington to give more details on the guarantees it could offer to protect Ukraine from another invasion.

“What will the United States of America do if Russia comes again with aggression?” he asked. “What will these security guarantees do? How will they work?”

-Agence France-Presse