"This conference addresses our needs to find a suitable atmosphere to open political paths to put an end to violence and counter-violence," the Palestinian leader told the meeting of representatives from about two dozen Western and Arab countries.

Abbas said experience had shown that security efforts could collapse unless they were backed by a "serious political track."

He called for renewed efforts to implement the US-backed "road map" plan for Middle East peace, stalled by violence and upstaged by Israeli Prime Minister Ariel Sharon's unilateral plan to withdraw from the Gaza Strip later this year.

British Prime Minister Tony Blair, hosting the one-day meeting, said resolving the Israeli-Palestinian conflict was a vital part of the struggle against extremism.

"There is probably no more pressing political challenge than to move this process forward," he said at the opening session.

Palestinian leaders want global backing for plans to reform their security forces and tackle corruption.

Most of all, they hope the conference will lead to an early resumption of talks on a final settlement -- something Israel wants to defer until after Palestinians have cracked down harder on militants and until after its own withdrawal from Gaza.

Palestinians want governments to press Israel to ensure that any Gaza pullout is part of the road map, not a one-off move that would perpetuate Israeli control of big West Bank settlements.

The one-day conference has been clouded by Friday's suicide bombing in Tel Aviv, which highlighted the fragility of the Israeli-Palestinian ceasefire declaration made three weeks ago.