With Palestinian leader Mahmoud Abbas (search) due at the White House this week, Israeli Prime Minister Ariel Sharon (search) is renewing calls for coordination between the two sides during Israel's planned withdrawal from the Gaza Strip (search) this summer.

The Gaza withdrawal plan was expected to be the centerpiece of a speech that Sharon was delivering Tuesday to the American Israel Public Action Committee, the powerful pro-Israel lobbying group, aides said.

Sharon, on a three-day visit to the U.S., said Monday that he believes his withdrawal plan provides a great opportunity for restarting peace talks with the Palestinians.

"If it will work, as we expect, we believe it might be a major change in the Middle East, and of course with the relations between ourselves and the Palestinians," Sharon told a group of Jewish leaders in New York.

But he said a resumption of talks based on the U.S.-backed "road map" peace plan remains far off. He said negotiations could only start if Abbas cracks down on Palestinian militant groups.

Sharon also reiterated his position that large blocs of West Bank settlements would remain part of Israel "forever," though he left the door open to turning over other areas of the West Bank under an eventual peace agreement. "Other places, all of that I think will be ... the final phase of the permanent agreement negotiations," he said.

The comments, which fall far short of Palestinian demands, were likely to be raised by Abbas in his meeting with President Bush on Thursday. Abbas is eager to restart talks on the road map, which calls for the establishment of an independent Palestinian state, and wants all of the West Bank.

Addressing the AIPAC conference on Monday, Secretary of State Condoleeza Rice said Bush would insist that Abbas dismantle all militant networks in Palestinian areas. She also said Israel has obligations as well, and that Bush will build with Abbas "a relationship that is based on the good faith that only democratic leaders can bring."

For now, Sharon is concentrating on his plan to uproot all 21 settlements in Gaza, and withdraw from four small settlements in the northern West Bank. The withdrawal is set to begin in mid-August.

Sharon announced the pullout as a unilateral move last year, while his nemesis, Yasser Arafat, was still alive. But since Abbas' election early this year following Arafat's death, both sides have expressed willingness to work together.

Those efforts, however, have hit a standstill amid Israeli accusations that Abbas isn't doing enough to crack down on militant groups. Abbas has secured a four-month cease-fire with Israel that has largely remained intact, but had not confronted violent groups directly.

Sharon said Monday that he believes Abbas wants to improve the situation and is hopeful cooperation will soon resume. But he said "only actions" would have a meaningful effect.

"In our part of the world, declarations and speeches and talk and promises are meaningless," Sharon said.

Sharon's speech Tuesday also was expected to touch on Iran's nuclear ambitions, which Israel has identified as a major threat.

Sharon renewed calls Monday for the U.N. Security Council to take action to prevent Iran from developing nuclear weapons, ratcheting up pressure on Tehran ahead of key negotiations with European leaders this week.

Sharon said Iran is "making every effort" to obtain nuclear weapons, despite its claims that its nuclear program is for peaceful purposes. Sharon called for an international effort, led by the United States with backing from Europe, to take the matter to the Security Council, which can impose sanctions on Iran.