Rice welcomes Mideast envoy Blair

At the same time, she defended the decision to limit Mr Blair's mandate to helping Palestinians develop their infrastructure and economy, saying his role would complement US-led diplomatic efforts - and that there was plenty of work for everyone.

"This is a very skilled, respected, historic figure in many ways in the world, who is absolutely dedicated to democracy, to building a better Middle East," Ms Rice said on board a plane en route to a high-level meeting in Portugal of the Quartet for Peace.

The meeting - which brings together the United States, the European Union, Russia and the United Nations - will be the first since the hard-line Islamic group Hamas wrested control of the Gaza Strip from the more moderate Fatah last month.

The power-grab split the Palestinian leadership and placed yet another obstacle in the way of a broad Middle East peace deal. But it also prompted Israel and the West to seek ways to shore up beleaguered Palestinian President Mahmoud Abbas.

Ms Rice said the timing of the talks - and of Mr Blair's first appearance as Mideast envoy - was propitious.

"There is a very good sense that his dedication now to helping the Palestinians build the institutions of statehood, to move forward on economic development and to press forward on helping to create a strong Palestinian partner is very well timed as we try to move forward toward the establishment of a state," she said.

While Mr Blair brings gravitas and enthusiasm to the role, critics say his limited mandate will make it difficult for him to achieve a breakthrough. Ms Rice, who as America's senior diplomat is charged with the role as chief peacemaker, defended the division of responsibilities.

Mr Blair's role "is something that is completely complimentary and if we all work together, and there is plenty to do, perhaps we can finally deliver".

The talks in Portugal, which currently holds the EU's rotating presidency, bring together Rice, UN Secretary-General Ban Ki-moon, EU foreign policy chief Javier Solana and Russian Foreign Minister Sergey Lavrov.