KIEV, April 27 - Top European Union officials met the Ukrainian leadership on Monday for talks on deepening trade links and efforts to bring peace to Ukraine, but worsening violence in the separatist-minded east clouded the summit, Reuters reported.

As President Petro Poroshenko met European Commission President Jean-Claude Juncker and European Council President Donald Tusk, Kiev's military reported intensifying attacks by pro-Russian rebels in the east and south-east.

One serviceman from Ukraine's government forces had been killed and three others wounded, a military spokesman said.

The EU-Ukraine summit was the first since a political and free trade association agreement was signed by Poroshenko's pro-Western leadership after the ousting of the Moscow-backed Viktor Yanukovych in a public revolt in Kiev in February last year.

Russia, under sanctions from the EU because of what Western governments and Kiev say is clear support for the rebels, has made no secret it opposes Ukraine's moves to integrate with the European mainstream.

It has secured a delay in implementation of the free trade deal, which will take Ukraine further away from Russia's orbit, until January 2016.

But Ukraine on Monday secured backing from the EU officials that there would be no more such delays despite Russian requests.

"Others want to postpone the entry into force of this free trade agreement," Juncker said in a clear reference to Russia.

"We don't think this would be a wise and a good idea. It has been postponed once. We are postponing, postponing, postponing. We have to have this free trade agreement enter into force on January 2016," Juncker told a new conference.

"After our negotiations, I think that no-one can have any doubt that the free trade agreement between Ukraine and the European Union will come into force from January 1 2016," Prime Minister Arseniy Yatseniuk said in televised comments from the summit hall.

EU officials said the summit had been called to give the near-bankrupt ex-Soviet country strong support for its reform program and efforts to achieve financial stability with support from the International Monetary Fund and the EU and by debt restructuring.

The EU particularly is pressing Ukraine to take radical moves to rid itself of endemic corruption and reform its corruption-prone energy sector, give regions more power to run their own affairs and improve the business and investment climate.

Juncker reiterated the EU would provide financial assistance of 1.8 billion euros. Separately, he pledged the European Commission would make further financial assistance of 70 million euros to ensure a "return to a safe environment" at the site of the Chernobyl nuclear disaster.

The assistance will go towards building a new safety structure round the existing sarcophagus of the reactor which exploded in April 1986 in what was then the world's worst nuclear accident. (rt/ez)