The United Nations special envoy, Alvaro de Soto, has said that a deal to reunify Cyprus can be reached over the next couple of days - but Greek Prime Minister Costas Simitis has cast doubt on the idea.

Alvaro de Soto expects to work through the night

In the hours leading up to the start of the EU summit in Copenhagen on Thursday, frantic negotiations were taking place in the city.

The hope is that at the same time as the EU invites Cyprus and nine other mainly eastern European states to become members, the UN can end 28 years of division on the island.

The latest talks involve the Greek and Turkish Cypriot communities, Greece and Turkey, the UN and the EU - with the United States urging them on enthusiastically.

Greek scepticism

The BBC's Chris Morris in Copenhagen says diplomats have been trying to find a solution to the Cyprus conundrum for decades, and this is the best chance yet.

Rauf Denktash is in hospital

Mr de Soto, said he expected to work through the night, negotiating with both Cypriot communities.

But Mr Simitis said he thought a deal was unlikely. He pointed out that the Turkish Cypriot leader, Rauf Denktash, was not in Copenhagen, and he doubted that anyone else would have the authority to sign an agreement.

Mr Denktash, who recently underwent heart surgery in the US was admitted to hospital in Ankara on Thursday, and is expected to remain there for a week.

His representative in Copenhagen is the foreign and defence minister of the self-declared Turkish Republic of Northern Cyprus, Tahsin Erturoglu.

Turkey 'positive'

Mr Simitis also pointed out that if a deal was really close, UN Secretary General Kofi Annan would have been present.

Greek Cypriots have protested against the UN plan in Athens

Mr Annan has said that he is ready to fly to Copenhagen, if needed.

Earlier a member of the Turkish Government delegation in Copenhagen, Egemen Bagci, told the BBC that Turkey took a positive view of the latest UN plan to resolve the dispute.

But in return for helping achieve agreement on Cyprus, Turkey has indicated it wants an improvement on the date of July 2005 it has so far been offered for the start of EU membership talks.

Turkish leaders will meet French President Jacques Chirac and German Chancellor Gerhard Schroeder on Friday to press their case for a date before 1 May 2004.