Vijay Nambiar, who led a three-men team sent by Secretary-General Kofi Annan to the region to assess the worsening Middle East crisis, made the appeal while addressing the Security Council at an open meeting on the regional crisis.

There were "serious obstacles to the achievement of a comprehensive ceasefire in the immediate future", said Nambiar, who is Annan's senior political advisor.

But he stressed the urgent need to achieve some form of "cessation of hostilities," which is "essential so that the captives are protected and released, humanitarian access is assured, civilian casualties are dramatically reduced, and the political space is opened to negotiate a full and durable ceasefire."

He called on the Security Council to unite in the coming days to dramatically reduce the devastating toll on civilians, and to quickly develop the framework for a political solution.

The UN mediator called for the building of the framework that would pave the way for such a ceasefire, some of which had been suggested by the UN chief Thursday in his briefing to the council and included a strengthened international peacekeeping force.

"A political package is needed that gives the Governments of Israel and Lebanon confidence that the horrors each country is now enduring will not be repeated," Nambiar said, proposing that such a package should ensure the end of the Hizbollah threat against Israel, and the full respect by all parties of the Lebanese government's sovereignty and control.

Annan proposed on Thursday a package of actions aimed at achieving a lasting solution to the conflict between Israel and Lebanon, including a call for an immediate ceasefire in Lebanon and Gaza, the release of kidnapped Israeli soldiers and the convening of an international conference.