UNITED NATIONS — On the eve of completing a total withdrawal from southern Lebanon, Israeli military officials yesterday began to question the ability of the Lebanese and international forces replacing them to face future threats from Hezbollah.

A meeting between the commander of the United Nations Interim Force in Lebanon, Major General Alain Pellegrini of France, and military officials from Lebanon and Israel “did not go well,” several officials close to the negotiations told The New York Sun. At issue were new concerns in Jerusalem that the rules of engagement employed by the enhanced U.N.force are not robust enough.

Those concerns come on the heels of several news reports that the European-led force will avoid confronting Hezbollah and that any attempt to curb the terrorist organization’s military capabilities will have to be approved by Beirut, where Hezbollah’s representatives carry significant political clout.

Over the weekend, the leader of Hezbollah, Sheik Hassan Nasrallah, emerged from hiding to announce in front of a huge crowd in southern Beirut that no one will disarm his organization, which he said has at least 20,000 rockets directed at Israel. His boasts, coupled with perceived international and Lebanese inaction, led Israeli officials to rethink the United Nations’ approach, diplomats close to the negotiations said.

One Israel Defense Force official, who was widely quoted in the Israeli press yesterday, even threatened that the small number of IDF troops still in Lebanon might not leave soon, contravening a plan to withdraw by Sunday and hand over control of the area near the border to UNIFIL.

“We told UNIFIL that we plan to pull our troops out of the 5% of Lebanese territory under our control byYom Kippur, but we haven’t said in what year,” the unnamed IDF official told the news Web site NRG after yesterday’s meeting at UNIFIL headquarters in Naqoura, southern Lebanon.

Defense Minister Amir Peretz, however, had told the Knesset’s foreign relations and defense committee earlier in the day that the last of several hundred Israeli troops in Lebanon would be out of the small sliver of land they still control by the end of this week or early next week.

Israel intends “to fulfill our commitment and to leave Lebanon as soon as conditions on the ground allow us to do so,” a Foreign Ministry spokesman, Mark Regev, told the Sun yesterday. But that commitment “does not take place in a vacuum,” he added. “It takes place within the full implementation of resolution 1701.”

That resolution, which last month created the conditions for the lull in the fighting between Israel and Hezbollah, includes several provisions designed to disarm Hezbollah, ensure that it does not rearm, and create a weapons-free zone in the Shiite stronghold between Israel’s northern border and the Litani River.

“From Israel’s point of view, the aspects of 1701 that call for complete disarmament of Hezbollah and the removal of armed Hezbollah from southern Lebanon are crucial elements,” Mr. Regev said.

Israel halted its offensive against Hezbollah last month when, under growing international pressure, its leaders were persuaded that they would be better off replacing IDF troops with international peacekeepers.

“They weren’t going to be able to degrade Hezbollah much more without threatening the stability of the Lebanese Government,” Secretary of State Rice told the New York Post’s editorial board, according to a transcript posted yesterday on the State Department’s Web site.

“And a crossover point I think came then where you had to look for a diplomatic solution that would allow the Lebanese Government to extend its authority and that’s what the resolution was about,” she added.

Diplomats close to the negotiations among Israel, Lebanon, and the United Nations said, however, that yesterday’s contentious session at Naqoura was an indication of Jerusalem’s growing distrust of that diplomatic solution — that a European-led force and a Lebanese army contingent will assume the responsibility of confronting Hezbollah.

Last week, General Pellegrini told the Jerusalem Post that peacekeepers will not actively engage Hezbollah guerrillas, even if Hezbollah attacks Israel. The New YorkTimes later quoted several top UNIFIL commanders who complained that the rules of engagement do not allow them to set roadblocks or search vehicles, even those that are obviously carrying weapons destined for Hezbollah.

According to the State Department’s Web site, Ms. Rice told the Times that “there probably ought to be a conversation with UNIFIL about how it sees its responsibilities.” In resolution 1701, she said, the force’s “mandate was written in a very robust fashion.”

A diplomat who requested anonymity said yesterday that Israel also is wary of some potential troop contributors to the new force, particularly the Malaysian soldiers. Malaysian officials announced their support for Hezbollah during the war, and even pledged to send troops to fight against Israel.