The hawkish prime minister, meanwhile, saw his popularity rating fall to an all-time low on Friday, with a fresh poll showing 57% of his fellow citizens are not pleased with him.
Assistant US Secretary of State for Near East Affairs William Burns, National Security Council number two Stephen Hadley and its Middle East director, Elliott Abrams, arrived in Israel on Thursday to discuss Sharon's plans to withdraw from 17 of 21 Gaza Strip settlements.
Sharon has said he will start implementing his disengagement plan in the next few months if there is no progress in the internationally drafted road map for peace with the Palestinians.
The three met on Friday morning with Foreign Minister Silvan Shalom and Sharon's chief of staff, Dov Weisglass, US diplomatic sources said, without elaborating on the content of the talks.
But Shalom has made no secret of his opposition to the disengagement plan and warned that its adoption could lead to far-right parties pulling out of Sharon's coalition and provoking early elections.
Israeli Foreign Minister Silvan
Shalom opposes disengagement
The foreign minister will travel to Washington next week to discuss the plan with US officials and will also meet with the United Nations General Secretary Kofi Annan.
Israeli Defence Minister Shaul Mofaz, who is in the United States, was slated to resume talks with officials in a bid to obtain their crucial backing ahead of a possible visit by Sharon.
Washington has insisted that the disengagement plan must be in line with the road map and include the West Bank.
"Any such steps, any moves towards disengagement, should be part of a strategic, comprehensive approach that takes into consideration not just Gaza, but the West Bank as well," said Burns deputy David Satterfield on Thursday.
The US envoys were also meeting later on Friday morning with Palestinian finance minister Salam Fayyad and Saib Uraiqat, the Palestinian minister in charge of negotiations, at the US consulate in Arab east Jerusalem, the sources said.
The two ministers were just back from Paris, where they accompanied Prime Minister Ahmad Quraya on an official visit.
Security after withdrawal
After talks with President Jacques Chirac, Quraya told reporters he would meet with Sharon if an agenda is agreed upon at a preparatory meeting Sunday.
He also said Palestinian security services "will be able to start getting organised and providing security," after Israel's Gaza withdrawal.
Egypt says border security will
come after Israel leaves Gaza
Security on Israel's southern border with Egypt once Sharon withdraws from Gaza was the focus of talks on Thursday in Cairo between Shalom, his counterpart Ahmad Mahir, Egyptian President Hosni Mubarak and his intelligence chief Omar Sulaiman.
Shalom obtained guarantees that Egypt would ensure security on that border.
According to Egyptian state media, Mubarak dispatched Sulaiman to Washington soon after the meeting as "part of Egypt's intense efforts to re-launch the Israeli-Palestinian peace process."
A Friday poll in the Maariv daily showed that only 33% of Israelis are happy with their prime minister, marking his lowest rating since he took office in February 2001.
In contrast, 57% said they were not pleased with Sharon and the remainder did not express an opinion.
Last week, another poll showed that 53% of Israelis would like to see Sharon resign.
Recent media reports have revealed that Sharon had business links with the family of Elhanan Tannenbaum, a controversial Israeli figure and reserve colonel recently released by the Lebanese Shia group Hizb Allah in a prisoner exchange.
Sharon's reputation had already been badly tarnished by a series of financial scandals for which he was interrogated by police.