After a week of Israeli bombardment of the Gaza strip, Israel, Arab countries and the United States are discussing how to create an international force that would safeguard an eventual cease-fire, diplomats said Friday.

A key part of the arrangement, they said, is that the main Palestinian rival to the ruling Hamas party would be asked to take charge of border crossings.

The diplomats spoke only on the condition of anonymity because the proposals are still in their infancy and could be overtaken by events, such as an Israeli ground incursion into Gaza. Israel's bombardment already has killed some 400 people, as many as a quarter of them civilians.

The most difficult aspect under discussion was how to bring Gaza's border crossings under the control of Palestinian Authority President Mahmoud Abbas' Fatah security forces, which Hamas violently ejected from the Mediterranean enclave in 2007.

Diplomats said they saw no chance now for restoring Fatah's control over Gaza, but it's a different question whether Hamas would agree to Fatah taking charge of border crossings if Israel opened them fully.

As envoys from the Arab League, including Abbas, head to the United Nations early next week to press for an end to the fighting, Hamas has drawn relatively little sympathy or support for restoring its full legitimacy as the power controlling Gaza. Instead, consensus is growing around the Bush administration's premise that there has to be a permanent stop to the rocket attacks on Israel.

"Promises from Hamas will not suffice. There must be monitoring mechanisms in place to help ensure that smuggling of weapons to terrorist groups in Gaza comes to an end," President George W. Bush will say in his weekly Saturday radio address. The White House released a transcript of the taped address Friday evening.

Much as it did during the brief Israeli-Lebanon war in the summer of 2006, the Bush administration has strongly backed Israel's right to self-defense while deflecting calls for an immediate cease-fire, which, in the U.S. view, wouldn't improve the underlying situation.

The strategy had mixed results in Lebanon. There's been no new outbreak of war between Israel and the Iranian-backed Hezbollah, and Lebanon's armed forces have deployed to south Lebanon for the first time in years. However, Hezbollah has been able to replenish its arsenal with some 40,000 rockets, according to Israeli estimates.

Robert Serry, the United Nations special coordinator for Middle East peace negotiations, said Friday that while talk of an international force for Gaza was premature, it could be part of an eventual cease-fire.

"If we have a cease-fire, we must learn from the lessons of the past. What we had in the first cease-fire was not a stable condition, so we need to look into possibilities like an international presence," Serry said in Jerusalem. He referred to an Egyptian-mediated truce between Israel and Hamas that collapsed last month.

An Israeli diplomat said Israel was open to an international force - although not under U.N. auspices - as long as it ensured that Hamas wasn't able to smuggle in new weapons and rearm in Gaza.

One option, officials said, is to revive and expand a European Union border-monitoring mission. The unit suspended work at Gaza's Rafah crossing with Egypt after Hamas' armed takeover of the Gaza Strip in June 2007.

U.S. officials said that the Bush administration had three goals: a permanent cease-fire, reopening Gaza's border crossings with Egypt and Israel to normal trade, and halting widespread weapons-smuggling into Gaza via tunnels from Egypt.

Israel won't agree to open the border crossings fully without assurances that the smuggling has ceased, U.S. and Israeli officials said.

While there's Arab and Western support for Abbas' U.S.-backed security forces taking control of the crossings, it isn't clear how that could be carried out. U.S. officials acknowledge that there's little chance that the Palestinian Authority, which controls the West Bank, could reassume political power in the Gaza Strip anytime soon.