The Quartet of Middle East mediators gathers for the first time with Tony Blair as special envoy on Thursday at a meeting expected to focus on a U.S. push to revive Israeli-Palestinian peace moves.
The Quartet meeting will be the first since Hamas Islamists seized control of the Gaza Strip from U.S.-backed President Mahmoud Abbas's forces last month and since the former British prime minister was named as its envoy.
The group, including the United States, Russia, the European Union and the United Nations, is expected to endorse U.S. efforts to restart long-frozen negotiations between Israel and the Palestinians on ending decades of conflict.
U.S. President George W. Bush announced this week he intends to hold a Middle East peace conference in the autumn.
"Bush's announcement will surely influence the dynamics of the meeting in Lisbon," said Portuguese Foreign Minister Luis Amado, whose country currently holds the rotating EU presidency and is hosting the meeting.
"I think the Quartet meeting could give a new impulse to the peace process in the Middle East."
It is years since Israel and the Palestinians last discussed issues at the root of the conflict -- final borders of a Palestinian state, the return of refugees and the status of Jerusalem.
U.S. Secretary of State Condoleezza Rice said the United States would keep leading Middle East peace efforts with Blair playing a "completely complementary" role as Quartet envoy.
She made clear she saw her role as dealing with the political issues.
