Greece and Turkey are joining expanded Cypriot reunification talks in Switzerland this week after direct talks between the leaders of the Greek and Turkish communities in Cyprus failed to show any signs of progress.

This second phase of a last-ditch United Nations initiative to reunite Cyprus will include Turkish Prime Minister Tayyip Erdogan and his Greek counterpart, Costas Karamanlis.

But in another setback to the process, Turkish Cypriot leader Rauf Denktash announced he would not attend the talks in Burgenstock because he doubts that progress can be made in the negotiations there. He has not formally declined the invitation or been in contact with U.N. Secretary General Kofi Annan.

If Mr. Denktash does not attend the Swiss meeting, Turkish Cypriot Prime Minister Mehmet Ali Talat will represent the breakaway northern sector of the island.

Sir Kieran Prendergast, U.N. Undersecretary General for Political Affairs, warned Mr. Denktash that final decisions have to be made in Switzerland and that anyone that not attending would be excluded from the process.

"Anyone who is not at Burgenstock is not in the process and the process is going to be finalized next week," said Mr. Prendergast. "What we are looking for is representatives of the Turkish Cypriot side who are empowered to take final decisions at Burgenstock - that is the requirement."

Mr. Denktash insisted he was not quitting as negotiator for the Turkish Cypriot side. Turkish Foreign Minister Abdullah Gul played down the statements about his withdrawal from the Swiss talks, telling journalists that Mr. Denktash has not withdrawn from negotiations. He said he is in constant contact.

U.N.-sponsored talks between the two communities since February 19 have failed to show any sign of progress in breaking the deadlock, which has divided the island for 30 years. Disagreements primarily center on territorial issues and property claims.

Switzerland has supported Cyprus's reunification talks for several years, and it was thought that meeting there would provide an ideal condition for the talks.

Swiss diplomat Didier Pfirter, a U.N. legal adviser on Cyprus, said all parties now needed to make an intense effort to reach agreement.

"There were good reasons to want the parties to be making this last effort in a very intense way, in an environment where everybody would be available around the clock, so it could really be a 24-hour, non-stop effort for a whole week," said Mr. Pfirter. "Basically, just informally be able to have as many contacts as possible and intense contacts in the hope of breaking the deadlock that exists and coming to an agreement."

The clock is ticking to reunite the island by the end of April. Failure to reach an agreement would mean the internationally recognized Greek Cypriot government in the south will join the European Union on May 1 on its own, further isolating the Turkish Cypriot north, whose self-declared republic is recognized only by Turkey.