EU pledges aid for new Chernobyl sarcophagus

The conference will mark the 25th anniversary of the Chernobyl meltdown and has been planned for several years, although recent events in Japan have added impetus to the occasion. A nuclear safety summit will take place immediately afterwards in the Ukrainian capital.

"Nuclear safety is a global issue that requires a global response," Barroso said in a statement ahead of the meeting. "We hope that our key partners will also step up their contributions in order to complete the works of the shelter by 2015."

France is expected to pledge at least €47 million, with a consortium made up of French construction companies Bouygues and Vinci winning a 2007 tender to build the 108-metre-high structure over Chernobyl's infamous No. 4 reactor, together with a separate facility to store spent nuclear fuel from the other units.

Engineers are planning to build the 20,000-tonne dome beside the Chernobyl reactor, using rails to then slide it over the cracked protective casing currently in place.

To this day, it is still unclear how many deaths were caused by the explosion, which spread radioactive material over a vast area but affected mostly Ukraine, Belarus and parts of Russia.

The World Health Organisation (WHO) suggests 4,000 deaths may have been caused as a result of escaped radiation at the plant, while others, such as Greenpeace, say the figure is tens of thousands more.

The anniversary comes amid a fresh debate on the wisdom of nuclear energy in the European Union following events in Japan. The German government recently decided to place a temporary moratorium on energy production at seven of the country's oldest plants.

A recently-published 2050 low-carbon 'roadmap' by the commission envisaged nuclear power taking up a larger share of Europe's energy mix in the years to come. But more detailed plans later this year are likely to include more non-nuclear options.

At the same time, a behind-the-scenes battle for influence between the EU and Russia has been evident in the weeks leading up to the international donors conference, with both sides keen to draw Kiev further into their orbit.

The EU is pressing for an Association Agreement with Ukraine, while Russian Prime Minister Vladimir Putin travelled to Kiev earlier this month to promote a special relationship with the Moscow-led Single Economic Space - a customs union that includes Russia, Belarus and Kazakhstan.

"On the future EU-Ukraine Association Agreement, we both confirmed our determination to conclude negotiations in the course of this year but there is still much work to do," Barroso said after a meeting with Ukrainian President Viktor Yanukovych on Monday.

So far, Yanukovych has attempted to keep both sides happy, suggesting one agreement does not exclude the other.

But commission officials are adamant that if Ukraine joins the Russia-led club, it will be impossible to sign a free trade agreement with the Union - a key component of the association treaty.