Presidential adviser Condoleezza Rice (search) is holding talks with Israeli and Palestinian officials this weekend in an effort to build on an agreement that withdraws Israeli security forces from northern Gaza (search).

Rice is due to meet separately with Palestinian Prime Minister Mahmoud Abbas (search) in Jericho and Israeli Prime Minister Ariel Sharon (search) in Jerusalem.

During her stay, she will keep a watchful eye on the agreement in principle reached Friday by the two sides for Israel to turn over security responsibility in northern Gaza to the Palestinian Authority.

Also, a truce in attacks by Hamas and (search) other militant Islamist groups on Israelis appeared to be emerging. On Saturday, a leader of the radical Palestinian group Islamic Jihad said his organization had agreed to a conditional three-month cease fire.

Secretary of State Colin Powell (search) called the security agreement, reached under the supervision of Assistant Secretary of State John Wolf, a "very positive development." He said Israel and the Palestinians would get to work on a similar arrangement for Palestinian security forces in Bethlehem on the West Bank (search).

"It is an early step," he said. "A lot more has to happen in the days ahead to make sure this opportunity is not lost. And this is the beginning of a long process that we hope will lead to the creation of a Palestinian state."

Powell said Wolf would appoint a U.S. team to monitor transfer of authority from Israel to the Palestinians and help resolve any problems. Later on, the Americans will look at economic and humanitarian issues.

"It's going to be a robust team and it's going to be engaged on a regular basis," Powell said.

"We are pleased with the progress we have seen," he said at a news conference.

The White House, welcoming the agreement, called it the "first significant joint step toward implementation of commitments" Israeli and Palestinian leaders made at a summit in Jordan with President Bush.

It is important the two sides take further steps leading to establishment of a Palestinian state living alongside Israel, the White House statement said.

The administration said a moratorium in attacks on Israelis by Hamas and other terror groups would be a welcomed development.

"The trends are moving in the right direction," Powell said. But he hesitated to confirm the conclusion of a truce accord. "I am anxious to see an actual agreement," he said.

State Department spokesman Richard Boucher said a truce "is not an end in itself." He said the U.S. goal was to have the Palestinian Authority dismantle the groups that have killed hundreds of Israelis.

"We would like every group to stop violence, to bar violence. That's what the Arab leaders have called for," the U.S. official said.

Palestinian leader Yasser Arafat's Fatah movement announced agreement on a three-month cease-fire as long as Israel stopped assassinating Hamas leaders. Bush's response was "I'll believe it when I see it" and he said Hamas and like-minded groups must be disbanded.

Rice was headed to the region from London, where she spoke to the International Institute for Strategic Studies.

Rice planned to have dinner Saturday night in the West Bank city of Jericho with Abbas and to continue talks with Palestinian officials Sunday while lower-level U.S., Israeli and Palestinian officials held separate trilateral meetings.

Rice also was due to meet Sunday with Sharon and, separately, with Foreign Minister Silvan Shalom and Defense Minister Shaul Mofaz.