The United States pressed Iran and Syria tonight to exert their influence over Lebanon's Hizbullah to halt rocket fire into Israel and return two captured soldiers to help end a week-old crisis.
Washington stuck to its position that its ally Israel was acting in self-defense and voiced reluctance to back calls for an immediate cease-fire while Hizbullah kept up cross-border rocket attacks that have drawn a wave of Israeli air strikes.
Under growing international pressure to step up US diplomatic efforts, Secretary of State Condoleezza Rice said there should be a cease-fire "as soon as possible when conditions are conducive to do so."
She said she would travel to the region "when it is appropriate and when it is necessary and will be helpful to the situation" but gave no indication of the timeframe.
Defending US efforts to quell the conflict, White House spokesman Tony Snow said it was up to Syria and Iran, Hizbullah's key supporters, to rein in the guerrilla group.
Analysts have said Iran may be using its clout with Hizbullah to show it can hurt US allies and interests if Washington goes ahead with efforts to get UN sanctions over Tehran's nuclear program.
"Israel is proceeding in the manner it sees fit to defend itself and its territory," Mr Snow told reporters. "We've got to remember who's responsible for this - Hizbullah. Hizbullah started this."
"And Iran and Syria, its backers, ought to be using their influence to get Hizbullah to stop firing rockets and return the soldiers," Snow added.
He pointed the finger at Syrian President Bashar al-Assad over the crises raging in Lebanon and Gaza.
"The president believes that at this point President Assad is not doing what he can to create stability, which would be to stop housing terrorist organizations and providing safe haven for them and permitting people to conduct terrorist operations or at least planning on his soil," he said.
Mr Snow reiterated the US appeal for Israel to act with restraint, saying, "We lament the death of innocents, whether they be in Israel or in Lebanon or in Gaza or anywhere else."
But he signaled US resistance to pressuring Israel into an immediate cease-fire that would leave Hizbullah's rockets still within range of Israel's northern towns and cities.
"A cease-fire that would leave the status quo ante intact is absolutely unacceptable. A cease-fire that would leave intact a terrorist infrastructure is unacceptable," he said.
Mr Snow said it was important to avoid further destabilization of Lebanon's fragile government but that it was too early to talk about sending a multinational security force to the Israel-Lebanon border.