US secretary of state Condoleezza Rice was due to meet Israeli deputy prime minister Shimon Peres in Washington yesterday as United States policy diverged from Israel's for the first time since the start of the war in Lebanon three weeks ago.
While Israel insists its military campaign against Hizbullah has several more weeks to run, Washington is seeking an early United Nations resolution to end the violence.
The shift in US policy reflects the Bush administration's impatience with Israel's failure to deliver a swift and convincing victory, and a growing fear in Washington that the outcome of the campaign could be an emboldened Hizbullah and inflamed Arab anti-Americanism.
President George Bush discussed the crisis with Dr Rice and national security adviser Stephen Hadley over dinner on Monday. A spokesman said later that the administration now saw the diplomatic action moving to the UN.
"The next step is to pursue a United Nations Security Council resolution that will establish a sustainable ceasefire on an urgent basis," the spokesman said. "This process began in New York today."
The administration's refusal to join calls for an immediate ceasefire has strained relations with European allies and has drawn criticism from Republican senator Chuck Hagel.
"The sickening slaughter on both sides must end now, this madness must stop," he said.
Israel's foreign minister Tzipi Livni acknowledged yesterday that the deaths of dozens of civilians at Qana had marked a significant diplomatic turning point against Israel.
The attack at Qana has also reduced Washington's diplomatic room for manoeuvre, making untenable its earlier policy of stalling diplomatic efforts to buy time for Israel to complete its offensive.
Despite Washington's promise to work towards an early UN resolution to end the violence, it remains at odds with most other Security Council members over the content of such a resolution.
There is broad agreement that a halt to hostilities should be accompanied by a prisoner exchange and the deployment of an international force in southern Lebanon. Washington is pressing for a ceasefire to be linked to a broader plan for peace in the Middle East. Israeli military planners believe that the ground operation to secure a narrow buffer zone north of the Lebanese border can be completed by the end of this week. Washington hopes to reach agreement by then on a UN resolution that would end the violence without leaving Hizbullah in a position to plausibly claim victory.
Some policy makers close to the Bush administration believe now that Israel and the US made a mistake in rejecting a ceasefire after the G8 summit statement in St Petersburg that blamed Hizbullah and Hamas for the conflict and called for a halt to violence on both sides.
In the intervening weeks, Israel has lost international support, failed to deliver a knock-out blow to Hizbullah and transformed the Islamist group's leader, Hassan Nasrallah, into a hero throughout the Arab world.
The US has seen its allies in Egypt, Saudi Arabia and Jordan destabilised, its chief antagonist in the region, Iran, has been strengthened, while American diplomatic capital has been expended on support for yet another failed effort to reshape the Middle East by force.