WASHINGTON (Reuters) - The White House on Monday backed efforts by Palestinian Prime Minister Mahmoud Abbas to negotiate a cease-fire with militants, but said he would ultimately need to disarm the groups.

Officials say a cease-fire could smooth the way for Israeli Prime Minister Ariel Sharon´s plan to pull Jewish settlers from Gaza later this year.

"A cease-fire can help end the violence," White House spokesman Scott McClellan said. "But ultimately we need to dismantle those terrorist organizations that exist," he told reporters ahead of talks between U.S. Secretary of State Condoleezza Rice and Dov Weisglass, Sharon´s chief diplomatic adviser.

U.S. President George W. Bush has enthusiastically backed Abbas, elected earlier this month to replace Yasser Arafat, whom Washington shunned as an obstacle to peace until his death.

McClellan praised Abbas for deploying Palestinian security forces in Gaza to stop gunmen.

Rice will visit Israel and the West Bank on Monday. She will later attend a conference in London on Palestinian reforms. The Bush administration is expected to provide an extra $200 million in aid this year to the Palestinians.

"This is a very hopeful period and a historic opportunity that we need to seize. And now is the time to do that," McClellan said. (© Reuters 2005 01/31/05)