UNITED NATIONS — Objecting to a robust French-led force that would help disarm Hezbollah, Lebanon and its Arab League partners yesterday blocked another French-American attempt to reach an agreed end to the war along the Israeli-Lebanese border.

Russia last night attempted to soften Washington’s position by proposing a 72-hour “humanitarian” pause in the fighting until the members of the U.N. Security Council can reach a diplomatic solution.

The American ambassador to the United Nations, John Bolton, however, dismissed the Russian idea, brought up in a late-evening meeting of the five veto-wielding members of the Security Council and later circulated to all 15 council members. The move would “divert attention” from his attempt, along with his French counterpart, Jean-Marc de la Sabliere, to seek a “permanent sustainable solution,” Mr. Bolton said.

According to diplomats involved in the talks, Beirut declined to allow a strong French-led force to enter the country and operate with the strongest mandate possible, under Chapter 7 of the U.N. Charter, which allows international troops to enforce the Security Council’s will, including by using firepower.

Lebanese diplomats, bolstered by representatives from Qatar, the United Arab Emirates, and the Arab League, announced at a meeting with the U.N. ambassadors of France and America yesterday afternoon that they would not sign off on the idea. The Arab refusal led to an unraveling of the deal, which was finalized by Washington and Paris.

“The problem is that the Lebanese, they do not accept Chapter 7 language,” the deputy Chinese ambassador to the United Nations, Liu Zhenmin, told The New York Sun after the five council permanent members met yesterday at the British U.N. mission.

After a week of frenzied negotiations among Paris, Washington, Beirut, and Jerusalem, the principals began yesterday with cautious optimism, as diplomats indicated a breakthrough was imminent.

Mr. Bolton did not exclude the possibility that at one point on Friday the council would adopt a resolution.

The plan was that foreign ministers of countries represented on the council would fly to New York, as would the main combatants, where a high-level Turtle Bay session would take place to supply the necessary dramatic background for a significant diplomatic war-ending solution.

The British foreign secretary, Margaret Beckett, boarded a plane yesterday and was scheduled to land in New York in the early evening. Foreign Minister Tzipi Livni of Israel, however, postponed her flight to New York late last night once details of the latest U.N. impasse reached her, Israel Radio reported.

On Wednesday, Prime Minister Olmert and Defense Minister Amir Peretz decided to postpone a major ground invasion into Lebanon after White House officials convinced them a diplomatic breakthrough was imminent.

“If our goals will be reached diplomatically, we would not act militarily,” Mr. Olmert told Undersecretary of State David Welch during a Jerusalem meeting, according to Ynet. “But if the international community fails to achieve the goals the government of Israel decided on as it began the military campaign, we would act with all our military might in Lebanon.”

Russia aimed to block precisely such an eventuality. After the meeting of the five permanent Security Council members last night, the Russian ambassador to the United Nations, Vitaly Churkin, told reporters that the French-American effort reached “a situation where no end to political negotiations is in sight.”

The resolution seemed very close, he said, “but we have been close for a while.” At the current pace, he said, people on both sides “will continue to be killed and the war will continue to be fought.”

As a result, Russia circulated a proposed resolution to members of the council that called for “an immediate and full cessation of hostilities for humanitarian purposes for a period of 72 hours.”

Mr. Bolton responded to the Russian proposal by saying, “I don’t think it is helpful to divert attention in seeking to get a permanent, sustainable solution.”

“We’re not playing games here. This is very serious,” he said. “I think we’ve got a realistic prospect for success.”

Mr. Bolton said he was still hopeful for a vote on the French-American proposal as early as Friday.

The breakthrough yesterday came when France agreed to send its troops to southern Lebanon early on, to bolster the weak U.N. force there now, known as UNIFIL. The previous proposal envisaged a cessation of hostilities after which Israeli troops would remain in southern Lebanon until a later date, when the French-led force would be deployed.

Beirut’s midweek announcement that the Lebanese army was ready to deploy 15,000 troops in the south changed the picture, however. Once France agreed to an early deployment yesterday, diplomats said, its force would resolve Israel’s concerns that Hezbollah would retake areas Israeli troops evacuated.

But Lebanon and its Arab League allies insisted that Israel should leave first. “The whole idea is for the Israeli forces, wherever they are on Lebanese territory, to withdraw,” the league’s secretary-general, Amre Moussa, said. “This is the game. This is the goal.”

To allay those concerns, the new proposal envisioned synchronized action, as the bolstered U.N. force would enter the evacuated areas alongside the Lebanese army in coordination with the withdrawing Israeli troops.

But for any of this to work, Israel and America demanded that the international force be bolstered by Chapter 7 provisions, so it would be allowed to stand up to Hezbollah and later to disarm it according to the council’s earlier resolutions. Beirut, where Hezbollah is part of the government, resisted this concept.