The United States and Russia clashed on Friday over Moscow's suggestion that Syria should be included in efforts to advance an Israeli-Palestinian peace settlement.

"Syria could play a constructive role," Russian Foreign Minister Sergey Lavrov said after a meeting of world powers to discuss Mideast strategy.

However, Secretary of State Condoleezza Rice expressed little enthusiasm for such a prospect. "I hope that it (Syria) will in fact try and play a positive role rather than a negative one," she told reporters.

The Bush administration has resisted expanding diplomatic ties with Syria, which it blames for lending support to radical Islamic groups Hezbollah in Lebanon and Hamas in the Palestinian territories.

The U.S. has also expressed reluctance to reach out to Syria and Iran in a regional effort to reduce violence in Iraq, arguing that both countries' actions show they have little interest in stabilizing the area.

Still, said Lavrov, "It is counterproductive to isolate anybody."

Rice said that dormant Mideast peace talks should resume despite an outbreak of violence among Palestinian factions.

"It doesn't help to talk about a timetable, but it does help to talk about a commitment," Rice said after her meeting at the State Department with foreign ministers from the United Nations, the European Union and Russia.

The gathering of would-be peacemakers came amid renewed fighting between Hamas militants and security forces loyal to the former ruling Fatah Party that has raised new alarm about a possible Palestinian civil war.

More than 100 Palestinians have been killed in internal violence since Hamas won parliamentary elections last year and formed a Cabinet.

Despite that violence, "there's simply no reason to avoid the subject of how we get to a Palestinian state," Rice said.

The international leaders reiterated the conditions they set for the Hamas-led Palestinian government to receive vital overseas financial aid and international political recognition.

Those include recognition of Israel, renouncing violence and embracing prior agreements between Israel and the Palestinians to work toward peace.

That statement was signed a year ago, days after Hamas won a surprise victory in Palestinian elections.

Hamas has refused to meet the terms, however, leading to a cutoff of direct international aid and a breakdown of services and order in the Palestinian territories.

World powers have largely abandoned hope that Hamas radicals will drop the anti-Israel positions and are looking for a new approach.

Rice was asked about the violence in Gaza and other Palestinian areas.

"We expressed our concern about events on the ground in the Palestinian territories. Obviously innocent people are being caught up in this violence and it needs to stop," she said.

But, she said, "The Palestinian people have waited a long time for a state and the Israeli people have waited a long time for the peace and security that would come from having a democratic neighbor."

The four-way meeting, convened by Rice, risked appearing irrelevant in light of the internal Palestinian disarray.

Any eventual political accommodation with Israel would require a Palestinian government unified and capable enough to negotiate lasting terms.

State Department spokesman Sean McCormack said the internal divisions are issues for the Palestinians alone to resolve.

The United States is looking for ways to revive peace efforts partly as a way to reassure Arab allies that it wants to improve the Palestinians' plight and solidify those allies against Iran.

Shiite Iran has close ties to Hamas, which the West considers a terrorist organization.

One goal of the session was to demonstrate tangible support for secular Palestinian President Mahmoud Abbas.

"The international community is going to do everything it can to settle the conflict between Israel and the Palestinians," German Foreign Minister Frank-Walter Steinmeier said before the meeting. He attended the session because Germany currently holds the European Union's rotating presidency.

Cease-fires between the two sides in recent weeks and months have quickly fallen apart — the most recent was announced early Tuesday.

In the latest fighting, gunmen waged battles in the streets with mortar shells, rockets and heavy machine guns.

Abbas appealed Friday for calm.

"I call on all parties in Gaza to stop these actions that harm the Palestinian people," he said.