Hassan Nasrallah, the leader of Hizbollah, said in a triumphalist speech to a rally of several hundred thousand people that "no army in the world" would be able to disarm its forces.

And in a direct warning to the Western-supported government of Lebanon, he called for a new "unity government" and declared that the administration of the Prime Minister, Fouad Siniora, was "unable to protect Lebanon, or to reconstruct Lebanon or to unify Lebanon." He said Hizbollah would only consider giving up its weapons when a "strong, capable and just government" was in place.

He insisted that Hizbollah – whose infrastructure, the Israeli government has argued, was severely eroded by the conflict – had emerged from the war stronger than it had been before it. "[It] has recovered all its organisational and military capabilities," he said. "It is stronger than it was before 12 July."

"There is no army in the world that can [force us] to drop our weapons from our hands, from our grip," he told the rally in the southern suburbs of Beirut. "Today we celebrate a great divine, historic and strategic victory."

While Israeli officials have said they would continue to target Hizbollah’s leadership, the Israeli Prime Minister Ehud Olmert’s administration appears to have decided to make no attempt to assassinate him in such circumstances.

The former Lebanese president, Amin Gemayel, a sharp critic of Hizbollah, said parts of the speech were "dangerous". He said that Mr Nasrallah – whose victory pronouncements have also been sharply criticised by the Ali Al-Amin, the Shia mufti in the southern Lebanese city of Tyre – was "linking giving up Hizbollah’s weapons to regime change in Lebanon and … to drastic changes on the level of the Lebanese government".

Mr Gemayel added: "This is very surprising and dangerous, and leads us to ask, what kind of government does [Mr Nasrallah] want for what kind of Lebanon?" He said Mr Nasrallah, on the one hand, "extended his hand" to various Lebanese parties but, on the other hand, was "confrontational and made some very serious statements". A laconic statement issued by the prime minister’s office said only that it welcomed the focus on the dialogue as a "good and constructive thing and opens future horizons".

Mark Regev, a spokesman for Israel’s Foreign Ministry, said: "The international community can’t afford to have this Iranian-funded extremist spit in the face of the organised community of nations."

In response to Hizbollah’s claim to still have more than 20,000 rockets, Mr Regev said that, according to the United Nations-backed ceasefire, Hizbollah "shouldn’t have any rockets".

Faris Soueid, a Christian politician close to Mr Saniora, insisted on Al-Arabiya television that the government would not bend to Hizbollah pressure. "I believe it will not scare the government of Fouad Saniora, It will not fall, not in the street and not because of political speeches."

Meanwhile, Ismail Haniyeh, the Palestinian Prime Minister, said he would not lead a "national unity" Palestinian Authority which recognised Israel. But he said Hamas was ready to establish a Palestinian state including the territory seized by Israel in the Six-Day War and would offer a long term ceasefire to Israel. Mr Haniyeh’s remarks appeared to contradict the statement in New York by Mahmoud Abbas, the Palestinian president, earlier that the Palestinian factions would form a coalition government that would recognise Israel.