Updated

The White House is not saying much about a European proposal to establish a Palestinian governing system that would leave Yasser Arafat as president, but create a position of prime minister where the real power would lie.

"It's not for the United States to write the Constitution for another people. That's for those people to do it for themselves.  And to be meaningful, it has to come from the Palestinian people," said White House spokesman Ari Fleischer.  "It's not something the United States can impose. But it certainly is something the United States looks to happen, because that's the best way to bring stability to the region.

Some Arab leaders have signed on to the plan, saying that through that method "Arafat reigns but he doesn't rule." But they say the idea is dead if the Palestinians think its being forced on them.

The White House flatly denied some claims made by Israeli Prime Minister Ariel Sharon that President Bush agreed that it is pointless to enter into the peace process until Arafat is gone. U.S. officials said that assertion "is not accurate" and add that Bush also did not agree that reform of the Palestinian Authority should be a precondition for peace talks, as Sharon claimed.

Bush might not agree to making reform a precondition for talks, but the White House said that the Palestinian authority must enact democratic reforms. And allegations the Palestinians used U.S. and European aid money to finance terrorist attacks will mean tight strings on the aid they're likely to receive to rebuild after the latest Israeli military incursion.

The White House is also cautious about Arafat's ability to demonstrate his authority by maintaining 16 Hamas members reportedly in custody.

Hamas officials say the arrest never happened and dared the Palestinian Authority to try to arrest them, saying that it would lose its credibility with the Palestinian people if it dared.

Hamas leaders were continuing to go about their business in the Gaza Strip — Hamas' headquarters — with Hamas founder Sheik Ahmed Yassin preparing for his daughter's wedding, his son Mohammad said.

The White House is concerned that the Palestinian Authority does not have any militants in custody, particularly since the PA has a history of making arrests under pressure, then quickly releasing the militants.

"We're looking into the reports of the arrests. I don't have anything really beyond what we've heard — that they allegedly have been arrested," White House spokesman Ari Fleischer said. "If people are engaged in murder, they should be held accountable and a good government would arrest them and take it seriously and keep them locked up."

On Wednesday, Bush praised a speech by Arafat condemning Tuesday's suicide bombing that killed 16 and forced Sharon to return home from Washington early.

In a speech on Palestinian television, Arafat said that he had ordered his security forces to prevent attacks on Israeli civilians.

Bush called the speech an "incredibly positive sign" and said that he hopes Arafat's "actions now match his words."

Israel's Cabinet decided Thursday that regardless of the speech, it would order troops to retaliate in the Gaza. A top Palestinian official responded that such action would further set back peace negotiations by increasing Palestinian "defiance and hostility to Israel."

Hassan Abdel Rahman, who heads the Palestinian Liberation Organization's Washington offices, said the Bush administration must intervene to stop the Israeli military.

"You cannot let Mr. Sharon have a free hand," he said, denouncing the prime minister as a war criminal, a bully and a murderer.

The Bush administration has not volunteered any guidance on an Israeli response nor has it been asked.

The administration is facing increasing pressures on how to respond to each side, saying that it is looking for a democratic and secure structure for Palestinian leadership, and it also wants Israel to begin negotiations on Palestinian statehood even before that structure is in place.

Meanwhile, Tziti Livni, a member of Israel's legislature and an adviser to Sharon, said at a separate Washington session that if terror attacks on Israel are not stopped there will be no chance for an agreement with the Palestinians.

At the same time, she said, Israel cannot negotiate with a Palestinian leadership headed by Yasser Arafat.

"Arafat is not willing to accept the existence of Israel" and will not implement the reforms recommended by Bush without "an outside force" exerting influence, Livni said.

Fox News' Wendell Goler and the Associated Press contributed to this report.