The senior European Union official in charge of the organization's expansion has urged Cypriot leaders to support the reunification plan announced Wednesday night so the entire island can join the EU on May 1.

The EU's Enlargement Commissioner Guenter Verheugen told the European Parliament in Strasbourg that the Greek and Turkish Cypriot negotiators had come very close to reaching an agreement on uniting Cyprus in talks that ended in Switzerland late Wednesday.

When they could not agree, U.N. Secretary General Kofi Annan finished the plan, as had been previously agreed he would. But the Cypriot leaders from both sides of the island do not like it.

Commissioner Verheugen urged the leaders to support the plan anyway.

"I must make it very clear that remarkable progress was achieved," he said. "And I think that we have now reached a stage where we need strong political leadership. And here I would call on the Greek and Cypriot leaders to do all they can to try and persuade the population of the island that the present plan represents the best solution that can possibly be achieved."

Mr. Verheugen said there is no alternative to the present peace plan. He said if this plan is rejected in a referendum scheduled for April 24, Greek and Turkish Cypriots will likely not have another opportunity to resolve their differences anytime soon.

Cyprus has been divided since 1974, when Turkish troops invaded the island, after Greek Cypriots staged a brief coup backed by a military government in Athens.

The latest peace plan aims to resolve one of Europe's longest-running disputes before the internationally-recognized Greek Cypriot government joins the European Union on May 1. If the reunification plan is approved, the northern ethnic-Turkish sector would join, too. If not, the area will continue its 30-year international isolation.

Mr. Verheugen also commended Turkey, which has 40,000 troops in northern Cyprus, for playing what he called a very constructive and cooperative role in the Switzerland negotiations. He also praised recent political and economic changes in Turkey, but said more reforms are needed.

Turkey has long wanted to join the EU, and European officials have said that being constructive in the Cyprus talks would help its efforts. The European Commission is expected to announce in October whether Turkey meets the political criteria to begin membership negotiations.