Washington ? As Israeli tanks encircled Yasser Arafat’s headquarters, President Bush cast fresh doubts Monday on prospects for Mideast peace with the Palestinian leader in power.

“No one has confidence in the emerging Palestinian government,” Bush said with Israeli Prime Minister Ariel Sharon at his side.

Sharon, too, suggested there won’t be peace until anti-Israeli terrorism ends and Arafat is replaced.

“We must have a partner for negotiations,” the prime minister told Bush. “We don’t see yet a partner.”

Sharon didn’t get everything he wanted from Bush during their hourlong session and separate lunch. The president stopped short of endorsing calls to expel Arafat, and aides said he would pursue political talks despite Sharon’s misgivings.

Even so, Sharon was pleased with the meeting’s outcome, said a senior official in the Israeli party. The official, briefing reporters on condition of anonymity, said Sharon told Bush that Monday’s military operation around Arafat’s Ramallah compound had been planned to occur several days earlier.

It was postponed because many of those being sought had fled the area, but then returned, apparently mistakenly believing that Israel would not initiate military action while Sharon was in Washington, the Israeli official said.

The official said that 52 were arrested, including one potential suicide bomber and a senior official of the militant Islamic Jihad group. Two car bombs were found, the official said.

The sixth meeting between Bush and Sharon is expected to be the president’s final major consultation session before he unveils a Mideast initiative that aides say will address the concerns of both Israelis and Arabs.

Bush met last weekend with Egyptian President Hosni Mubarak, who wants Israeli troops to withdraw from territories occupied since 1967. Sharon has ruled that out, a sign of how difficult Bush’s juggling act will be.

His new Mideast policy, expected as early as this month, will put a premium on changes in the Palestinian Authority to give Israelis hope for security. At the same time, he intends to push for concrete steps toward a Palestinian state as sought by Arab leaders such as a possible timetable for negotiations, aides said.