Kofi Annan, the UN secretary-general, had called earlier on Monday for a "cessation of hostilities" between Israel and Hezbollah to enable a well-armed international "stabilisation force" to be put together.
Speaking from the sidelines of the G8 summit in Russia, Annan had said: "We need to get the parties to agree as soon as practicable to a cessation of hostilities to give us time and space to work.
"I appeal to the parties to focus their targets narrowly and to bear in mind that they have an obligation under international humanitarian law to spare civilian lives [and] to spare civilian infrastructure."
Annan, who had earlier spoken to Tony Blair, the British prime minister, also said: "The sooner decisions are taken by the council, the better it is, but the parties need not wait for their full implementation to start the cessation of hostilities and to spare civilians."
But Israel, which has been attacking targets all over Lebanon in retaliation for missile attacks by Hezbollah, the armed Lebanese group which is also holding two Israeli soldiers, said it was too soon to consider such a proposal.
Miri Eisin, an Israeli government spokeswoman, said: "I don't think we're at that stage yet. We're at the stage where we want to be sure that Hezbollah is not deployed at our northern border."
Elsewhere at the summit in St Petersburg, the French president announced that he was to send his prime minister to meet the Lebanese prime minister in Beirut in a gesture of solidarity.
Jacques Chirac's office said in a statement that the president "has decided to send the prime minister to Beirut today to meet Lebanese prime minister Fouad Siniora and convey to him the support of France and the solidarity of the French people with the Lebanese people in their ordeal".
Support for Lebanon was also voiced by Egypt, which dismissed as weak a G8 statement about the conflict.
Ahmed Abul Gheit, the Egyptian foreign minister, said on national television on Monday: "The final statement adopted by the G8 leaders concerning Lebanon lacks in strength."
The G8 statement reflected arguments between the United States, which had wanted to back Israel and what it called its right to self-defence, and countries such as France that condemn Israeli action as disproportionate.
The agreed statement eventually said: "The immediate crisis results from efforts by extremist forces to destabilise the region and to frustrate the aspirations of the Palestinian, Israeli and Lebanese people for democracy and peace."