Israeli warplanes and heavy artillery bombarded scores of Hezbollah targets across southern Lebanon as Israeli infantry troops waged an intense firefight with Hezbollah militia near the group's stronghold of Bint Jbail, the Associated Press reported.

At the East Room press conference, Bush and Blair, the president's closest military ally, presented a united front, saying the role of a U.N. force would be to assist Lebanon's own military in taking control of territory in southern Lebanon where Hezbollah militia units and their Syrian backers have long held sway.

Syria withdrew its uniformed forces from southern Lebanon after a 2004 U.N. resolution calling for the area to be returned to Lebanese government control. Hezbollah, though, which is also supported by Iran, has maintained effective control.

"We want a Lebanon free of militias and foreign interference," said Bush, who has backed the elected government led by Siniora.

Blair said the U.N. force would not "fight their way in," but would deploy, instead, only with the approval of Lebanon, Israel and Hezbollah.

With Hezbollah not officially represented in the diplomacy, however, neither leader explained what incentive the militant group might have to agree to a cease-fire. Its guerilla forces have fought Israeli troops to a tactical draw across parts of south Lebanon and has turned Arab opposition to its early raids into widespread support.

"The leadership is intact, the arms supply seems to be ongoing, and hence their deterrent capability, and in its ground battles the party's inflicted very heavy losses on Israel and, of course, they've paralyzed the country of Israel," said Amal Saad-Ghorayeb, assistant professor of politics at the Lebanese American University in Beirut. "They're already considering it a victory."

Bush, though, appeared to leave room for negotiations. While he referred to a U.N. resolution two years ago that called for "the disbanding and disarmament" of Hezbollah's militia units, he did not explicitly demand that the force be dismantled.

And while he called for the release of two Israeli soldiers who were captured on July 12, sparking the fighting, he did not rule out the kind of prisoner exchange Hezbollah has insisted upon and also made clear that an Israeli troop withdrawal from southern Lebanon would be part of any U.N. resolution.

Under those terms, said Saad-Ghorayeb, "maybe a compromise can be worked out."

At U.N. headquarters in New York, U.N. Secretary-General Kofi Annan also suggested that there is room for diplomatic maneuvering on the question of dismembering Hezbollah,

which has a political arm represented in Lebanon's elected government.