Israel wants the United States and Western countries to make halting uranium enrichment a condition for renewing talks with Iran, a senior Foreign Ministry official says.

The official said Israel had raised the subject in talks over the past two weeks with the United States, Britain, France, Germany and other countries.

Prime Minister Benjamin Netanyahu, who left for Canada on Thursday, is expected to broach the issue in his talks in Washington next week.

Two weeks ago Iran sent a letter to Catherine Ashton, the European Union's foreign policy chief, saying it was interested in renewing the negotiations with six world powers - the United States, Russia, China, Britain, France and Germany.

Ashton, who is coordinating the talks with the Iranians, has said in recent days the dialogue with the Iranians might be resumed in April, probably in Turkey.

U.S. Secretary of State Hillary Clinton said at a Senate hearing on Wednesday that if the talks with Iran reopen, they will be tough.

Foreign Ministry sources said Israel believes that the Iranians have no real intention of negotiating over their nuclear program and are merely trying to buy time.

Israel has made it clear to the United States, Britain, France and Germany that if they enter into a dialogue with Iran, they must set clear conditions and a rigid timetable.

"The most important condition to set before the Iranians is halting the uranium enrichment concurrently with the negotiations," a Foreign Ministry source said.

The possibility of opening negotiations with Iran came up in Israel's talks about a week ago with Tom Donilon, the U.S. national security adviser. It also came up in Defense Minister Ehud Barak's talks with senior White House officials this week.

At his meeting with U.S. President Barack Obama, Netanyahu is also expected to raise Israel's concern that the talks with Iran will waste valuable time and achieve nothing.