UNITED NATIONS — After weeks of pleading with the U.N. Security Council to impose an end to the fighting in Lebanon, the Arab League yesterday forged a delay in the adoption of a French-American proposal for a council resolution that would call for a cessation of hostilities.

Complicating the situation further, Beirut announced yesterday that it is ready to deploy 15,000 troops in southern Lebanon, a statement designed to force changes to the draft resolution proposed over the weekend by France and America.

The announcement came after yesterday’s summit in Beirut, where Arab foreign ministers expressed opposition to several provisions of the proposed resolution and demanded that Israel be forced to withdraw from southern Lebanon, where it sent troops in recent days to disarm Hezbollah.

The Security Council has long demanded the deployment of Lebanon’s army in the south and the disarmament of Hezbollah, and yesterday’s aboutface in Beirut forced some rethinking on the proposed resolution.

“It is a significant element” that will have to be taken into account in new negotiations on the proposed resolution, a French diplomat told The New York Sun yesterday, speaking on condition of anonymity. He said the French ambassador to the United Nations, Jean-Marc de la Sabliere, and his American counterpart, John Bolton, met yesterday to tackle the new Lebanese proposal.

“I think it will have to be acknowledged,” an American official who requested anonymity said. He added, however, that the Lebanese announcement should not change the proposal significantly. American and French diplomats have told council members in the last few days that any changes made to the hard-fought text would entail long delays and major complications.

Nevertheless, the latest development and its ramifications for the French-American proposal are likely to delay further the planned Turtle Bay vote on the proposal by the council’s 15 foreign ministers. The ministers now are not expected to convene before tomorrow evening.

Tonight, instead, three Arab League officials, including Secretary-General Amre Moussa, will address the council to present new objections to at least three provisions in the French-American proposal.

“We need to make sure that the Israeli forces withdrew behind the blue line,” the league’s U.N. observer, Yahya Mahmassani, told reporters yesterday, referring to the internationally recognized border. The resolution also must “tackle” the issue of Shebaa Farms, he said, which “must be put under the authority of the U.N., pending its delineation and demarcation.”

Mr. Mahmassani also rejected the proposal’s distinction between the two Israeli soldier abducted by Hezbollah and Lebanese prisoners long held in Israel. The current proposal “has a discriminatory tone and we don’t accept it,” he said.

“In our view, all three changes are necessary,” the acting Lebanese foreign minister, Tarek Mitri, told the Sun yesterday. But other Arab diplomats said the most important change should be a demand that Israeli troops leave Lebanon once the fighting ends.

The French-American proposal did not demand an immediate withdrawal of Israeli forces. Israel said its forces would withdraw only once a multinational force is created and deployed to assure that Hezbollah’s army is dismantled.

“Whatever happens in the U.N., we must not create a vacuum into which Hezbollah and its sponsors are able to move more weapons,” President Bush told reporters yesterday in Crawford, Texas.

Hours prior to the announcement in Beirut, Mr. Bush added that all sides agreed that the government of Prime Minister Siniora “needs to have the Lebanese armed forces move to take care of this vacuum that has been existing in the south.”

After arguing for two years that the Lebanese army was unable to disarm Hezbollah and deploy in the south, Lebanon’s information minister, Ghazi Aridi, said yesterday that the government “stresses its willingness to send a 15,000-strong Lebanese army force to deploy in south Lebanon as Israeli forces pull back behind the blue line.” The decision, he added, “should open the way for the amendment of the draft resolution in accordance with Lebanese demands.”

Israelis greeted the announcement with skepticism. A Jerusalem official who requested anonymity said the Lebanese army has not been able to control Hezbollah and cannot be trusted to do so now.

While some diplomats said yesterday that the proposed resolution might be changed to accommodate Mr. Siniora’s demand to transfer Shebaa to international custody, Mr. Bolton said the issue was settled in 2000, when the council adopted a report by Secretary-General Annan certifying Israel’s withdrawal from all of Lebanon and determining that Shebaa is Syrian territory.

Asked about Hezbollah’s argument that it is armed only to end Israel’s occupation of the landlocked area of Shebaa, Mr. Bolton said, “It is surely a pretext that Hezbollah uses — that it maintains anti-ship cruise missiles in its arsenal in order to liberate Shebaa Farms.”