The head of the EU's executive commission and the chairman of the 27 EU national leaders travelled to Kyiv to demonstrate support for Ukraine as the first anniversary of Russia's February 24, 2022, invasion of its neighbour approaches.

"There will be no let up in our resolve. We will also support you every step of the way on your journey to the EU," EU chairman Charles Michel wrote on Twitter on Friday morning under a picture of himself on a central Kyiv square.

There were no immediate reports of fresh missile strikes following the air raid warning.

Zelenskiy is calling for more punitive measures against Russia by the European Union but new sanctions the bloc is preparing for the anniversary are set to fall short of his government's demands.

Kyiv applied to join the bloc days after Russia invaded last year.

The EU has embraced the application, although it has rebuffed Ukraine's calls for a fast track to membership while the country is at war.

"The EU will support Ukraine and the Ukrainian people against Russia's ongoing war of aggression for as long as it takes," Michel, Zelenskiy and EU executive commission head Ursula von der Leyen will say in a joint statement, a draft of which was seen by Reuters in advance.

EU officials have listed multiple entry requirements, from political and economic stability to adopting various EU laws.

The process is likely to take years.

"Some may want to speculate about the endgame but the simple truth is that we are not there yet," an EU official said.

EU officials said subjects discussed on Thursday included more arms, money and energy support for Ukraine, better access for its products in the EU market, tightened sanctions on Moscow and efforts to prosecute Russian war crimes.

The German government has approved the delivery of Leopard 1 tanks to Ukraine from stocks and is in talks to buy back 15 Gepard tanks from Qatar to send there, the Sueddeutsche Zeitung newspaper reported on Friday, citing government sources.

The Leopard 1s are not as advanced as the Leopard 2s Germany and other countries pledged last week but could be delivered sooner.

The EU has demanded more anti-corruption measures from Ukraine, which is perceived as having endemic state graft, saying it must build a credible track record.

To that end, Zelenskiy has announced dismissals and investigations of some officials in the past two weeks, pointedly saying that the defence ministry needs to be clean.

Authorities were investigating senior military officials in two cases of suspected corruption, officials said on Thursday.

Separately, a criminal group suspected of embezzling state funds by selling overpriced eggs and other foodstuffs to defence officials had been arrested, the State Bureau of Investigation said.

This week, the authorities raided the homes of one of Ukraine's most prominent billionaires and a former interior minister and announced an investigation into what they called a billion-dollar fraud at the biggest oil company and refinery.

The EU-Ukraine summit coincides with an intensification of Russian pressure on Ukrainian forces in eastern battlegrounds and in the northeast and south.

Ukraine says Moscow is sending thousands of soldiers and mercenaries to their deaths in human wave attacks for small gains, to appease political masters.

Reuters was not able to verify battlefield reports.

Australian Associated Press