Geir Pedersen, the representative of Kofi Annan, the UN secretary-general, in Lebanon, said on Saturday: "After the Lebanese government meets today and after the Israeli cabinet has met tomorrow, we do expect to see an immediate cessation of hostilities.
"The cessation of hostilities should take place as soon as possible. Too many lives have been lost," he said after meeting Fawzi Sallukh, the Lebanese foreign minister.
Pedersen said he had discussed details of the resolution adopted by the UN Security Council on Friday that called for the cessation of hostilities and the deployment of a 15,000-strong international peacekeeping force.
"I also emphasised that the spirit of the resolution is that it calls for an end to the hostilities immediately and that all parties will be working in favour of that," Pedersen said.
"We should use this opportunity to stop the fighting and to relieve the situation for the civilian population and make sure that we will have real access to the civilian population."
Asked how hostilities could come to an end, Pedersen said: "By all parties immediately respecting the resolution."
In Jerusalem, Alvaro de Soto, the UN's Middle East envoy, said he expected fighting to wind down over the next two days even as Israel launched a new ground offensive.
"I think that what we should see in the next 24 or 48 hours at most is a reduction of violence. This would be normal," he told AFP, saying that implied a cessation of hostilities but not necessarily a full Israeli pullout.
"We are asking them [Israeli forces] to withdraw behind the blue line only once the Lebanese government and UNIFIL have been deployed. And this can take a few days but a cessation of hostilities should not wait for the deployment."
He said he expected Israel's operation to wind down as soon as the Israeli and Lebanese governments confirm their acceptance of the resolution.
The Lebanese cabinet was due to meet on Saturday and Israeli ministers will meet on Sunday.