TEL AVIV, Israel - Prime Minister Ariel Sharon of Israel offered tentative backing last night for a U.S. "road map" to an Israeli-Palestinian peace, including creating a Palestinian state covering part of the West Bank and the Gaza Strip.

But he couched that support in a series of strict conditions, including the removal of Palestinian leader Yasser Arafat and sharp limits on Palestinian security forces, which could prove impossible to implement soon.

And he reiterated his insistence that all attacks on Israelis must end before any concessions would be made.

Sharon, speaking in a suburb of Tel Aviv at a conference on Israeli security, said the Israeli government had agreed "in principle" to endorse a so-called road map that the Bush administration offered in late October to create an independent Palestinian state by 2005.

The proposal, which has been supported by the United Nations, Europe and Russia, calls for a three-step process that would start with a mutual cooling of Israeli and Palestinian attacks and move toward forming a new Palestinian government.

It would end further Israeli settlements in Palestinian lands and, at its climax in 2005, lay out clear borders for a Palestinian homeland and define the status of Jerusalem, a holy city for three of the world's major religions.

'Reasonable, realistic'

Sharon called the U.S. proposal "a reasonable, realistic and, I believe, attainable plan which will create a real chance to reach an agreement."

He pledged to bring the plan before any government he would lead after Israel's national elections on Jan. 28, which Sharon's Likud Party is widely expected to win.

Sharon's remarks last night were his most direct statement to date on the conditions he would accept as part of a permanent settlement of the Palestinian conflict.

He endorsed creating a homeland for the estimated 3 million Palestinians on territory that would cover about 40 percent of the West Bank and three-quarters of the Gaza Strip.

Saeb Erekat, a senior adviser to Arafat, dismissed Sharon's statements.

"Sharon is repeating his ideas of a long-term interim solution," he told Reuters. "The only road to peace is when Israel withdraws to the June 1967 borders."

Sharon last night effectively ruled out a permanent Israeli presence in all the areas its military has occupied since a Palestinian uprising began in September 2000.

Israeli forces have clamped down on major towns and roads in the West Bank and Gaza in an attempt to stop the infiltration of suicide bombers who have killed hundreds of Israelis during the 16-month conflict.

In some areas, Israeli forces have reinvaded after previously withdrawing.

Sharon said that occupation was a temporary response to what he called "security demands, and does not represent a political change of status."

"Israel will not return to rule in territories from which it has previously withdrawn," he said.

No set timetable

His outline nevertheless differed in some respects from the published versions of the plan backed by the White House, the European Union, the United Nations and Russia.

While the U.S. plan calls for a provisional Palestinian state by 2003 and a final agreement by 2005, the staged plan Sharon described would have no set time schedule, relying instead on evidence of concessions by the Palestinians.

"The American plan defines the parties' progress according to phases. The transition from one phase to the next will not be on the basis of a predetermined timetable," he said.

"It is clear to all that Israel can no longer be expected to make political concessions until there is proven calm and Palestinian governmental reforms."