JERUSALEM (CNN) -- Israel's Security Cabinet has approved an expansion of the ground campaign against Hezbollah guerrillas in Lebanon, Israeli officials said early Tuesday.
The announcement came hours after Israeli Prime Minister Ehud Olmert said his military was inflicting heavy damage on Hezbollah and rejected international calls for a cease-fire until Israel has pushed the Shiite Muslim militia back from its borders. ( Watch Israeli troops move toward Lebanon's border -- 2:26 )
"Quite a few days of fighting are still before us," Olmert told a conference of local officials.
The Israeli Security Cabinet last week rejected a call from military leaders to widen the Lebanon offensive but authorized a call-up of about 15,000 reserve soldiers. There was no immediate explanation for the reversal.
Reuters, quoting Israel Radio, reported 15,000 reservists would be called up, but it is not clear whether those troops are the ones already authorized or extra troops.
Other developments on Monday pointed to a lengthening of the 20-day-old conflict.
The United Nations Security Council postponed indefinitely a meeting on setting up a new peacekeeping force for the area.
President Bush said Monday there could be no cease-fire until Hezbollah was reined in and international borders respected, reiterating the U.S. stance on the conflict. (Watch Bush call for 'a cease-fire that will last' -- 3:22)
Meanwhile, Hezbollah's Al-Manar television station claimed Hezbollah missiles hit an Israeli warship. An Israeli security source said no Israeli vessel had been hit, according to Reuters news service.
Reuters also reported that Hezbollah said the attack was retaliation for Sunday's bombing of Qana, Lebanon, that killed at least 54 civilians. ( Watch how the massive blast made a sanctuary into a tomb -- 4:45 )
The airstrike -- which killed many children and sparked international outrage -- threatened to derail work toward a resolution in the conflict between Israel and Hezbollah guerrillas.
Israel has called the Qana airstrike a tragic mistake, and Olmert apologized for the pain the Lebanese people have endured. But he added, "We are fighting terrorists who know no bounds."
Syrian President Bashar al-Assad on Monday directed his country's military to heighten its readiness, vowing to back Lebanese resistance against Israel, the state news agency SANA reported Monday.
Dan Gillerman, the Israeli ambassador to the United Nations, said he was "not really worried" by Monday's Syrian declaration.
U.N. talks on hold
At the United Nations, a Security Council meeting on planning for a new peacekeeping force had been delayed "until there is more political clarity" on the path ahead in the Middle East conflict, Reuters news agency reported
U.N. Secretary-General Kofi Annan had called the meeting last Friday, but the world's major powers have said no force can be put in place until fighting stops and Israel, Lebanon and Hezbollah agree to its deployment, Reuters reported.
Despite an agreement to stop airstrikes for 48 hours, Israel dropped bombs in southern Lebanon on Monday.
In its agreement, Israel had reserved the right to hit targets that it considered an immediate threat. (Watch Lebanese town heavily damaged -- :44)
But the Israeli army said Monday's strikes near the Lebanese village of Tayba were meant to protect ground forces operating in the border area and were not aimed at specific targets.
The Israeli military expressed regret that one of the strikes hit a Lebanese military vehicle outside Tyre, Lebanon.
The Israel Defense Forces said it was unclear how many people were killed. Earlier, a senior Lebanese Interior Ministry official said the airstrike killed an aide to a Lebanese general and wounded three soldiers. The general survived the attack, the official said.
The IDF said it thought the car was carrying a senior Hezbollah militant involved in directing rocket fire on Israel.
Teams from the Red Cross and United Nations on Monday arrived in the southern Lebanese town of Bint Jbeil to survey the damage and evacuate residents, a day after heavy fighting reduced much of the area to rubble.
Israeli troops enter village
Also Monday, Israeli troops entered the southern Lebanese village of Aita Al-Shaab, according to the IDF.
"There is an operation going on over there -- this is the first time troops have been in this area," an Israeli army spokesman told Reuters.
Hezbollah said its guerrillas were engaging the advancing force in fierce fighting, Reuters reported.
Earlier Monday, the IDF said its aircraft fired on open fields surrounding its ground forces in the Tayba area. Three Israeli soldiers in the area suffered minor injuries after Hezbollah fighters hit their tank with a missile, an Israeli army spokesman said.
Two Hezbollah rockets hit in an open area of the northern Israeli town of Kiryat Shmona on Monday, but no casualties were reported, Israeli police officials said. The firings marked the first Hezbollah rocket attacks into northern Israel from southern Lebanon in a day.
The conflict began July 12 when Hezbollah captured two Israeli soldiers and killed three others in a cross-border raid.
Israeli airstrikes and artillery have pounded Lebanon since then, leaving nearly 500 people dead, Lebanese Internal Security Forces said. Hezbollah has responded by firing scores of rockets a day into northern Israel, killing at least 18 Israeli civilians, according to IDF.
Clashes with Hezbollah have left 33 Israeli troops dead, IDF said. Hezbollah's casualties were not known.
Bush, speaking in Florida on Monday, said Israel had the right to defend itself and called on Iran and Syria to stop aiding Hezbollah.
"Iran must end its financial support and supply of weapons to terrorist groups like Hezbollah," Bush said. "Syria must end its support for terror and respect the sovereignty of Lebanon." (Full story)
U.S. Secretary of State Condoleezza Rice, speaking earlier Monday, said she believed a resolution to the crisis could be reached this week. (Full story)
'Heavy blow' to Hezbollah
In New York, Olmert's deputy, Shimon Peres, said Israel's problem is with Hezbollah's Syrian and Iranian backers, not Lebanon.
"Though Hezbollah is a Lebanese body, they don't serve any Lebanese purpose," he said. Their purpose, he said, is to "make Lebanon part of the sphere of influence of Iran." (Full story)
In Olmert's Monday speech, he said Hezbollah has suffered a "heavy blow" in the fighting. Israeli troops and airstrikes have inflicted serious damage to Hezbollah's capacity to launch rockets into Israel, and its supply routes from Syria have been hampered, he said.
"We will stop the war when the [rocket] threat is removed ..., our captive soldiers return home in peace, and you are able to live in safety and security."
"We are paying a very precious and almost unbearable price in terms of loss of life, major damage to public and private property and tranquility -- and we're not prepared to give up our right to live perfectly ordinary lives, which are not subject to terrorism and hate and fanaticism," Olmert said.
CNN's Nada Husseini, John King, Elise Labott, Richard Roth and Ben Wedeman contributed to this report.