World powers called on Friday on Arab states to honor their financial and political pledges to help the Palestinians in their U.S.-backed Middle East peace effort with Israel.

The call was made in a statement at talks in London between the Quartet of Middle East peace negotiators made up of the United Nations, the United States, the European Union and Russia.

"The Quartet called for all donors to follow through on pledges made...The Quartet encouraged the Arab states to fulfil both their political and financial roles in support of the Annapolis process," the statement.

The statement voiced "deep concern" over humanitarian conditions in the Gaza Strip which has been under a stringent siege imposed by Israel since the Islamist Hamas movement took over power there in June 2007. Israel says the blockade is aimed at stopping Hamas rocket attacks into Israel.

"The Quartet called for continued emergency and humanitarian assistance and the provision of essential services to Gaza without obstruction. The Quartet expressed its continuing concern over the closure of major Gaza crossing points given the impact on the Palestinian economy and daily life," it said.

It also called on Israel to freeze all settlement activity and to dismantle outposts erected since March 2001, which the Palestinians and other countries say are an impediment to the peace process.

U.S. Secretary of State Condoleezza Rice told reporters earlier as she flew to London for the talks that "It's extremely important that people pay their pledges... States that have resources ought to be looking not for how little they can do, but how much they can do."

Rice did not mention any names but a senior U.S. official made clear Washington had in mind oil-rich Arab states whose contributions he called "woefully short."

Of $717.1 million in budget support for the Palestinians promised by Arab League members, only $153.2 million has been delivered, all of which came from three countries: Saudi Arabia, the United Arab Emirates and Algeria.

Donor states to urge Israel to lift W. Bank roadbocks, open borders

Donor states to the Palestinian Authority are expected to express grave concern for the suffering of the Palestinian population in the Gaza Strip at a conference that opens Friday in London.

A meeting of the Middle East Quartet of peacemakers will take place on the sidelines of this conference, chaired by UN Secretary General Ban Ki-moon and attended by several Arab foreign ministers. They will discuss ways of developing economic institutions in the West Bank and Gaza.

Diplomatic sources said the donor states' closing statement will call for the opening of the Gaza border crossings and express concern over Israel's increasing traffic restrictions in the West Bank and Gaza Strip.

Conference delegates will present a World Bank report censuring Israel for not doing enough to help the Palestinian Authority by removing roadblocks or reducing traffic restrictions to help revive the Palestinian economy.

According to UN figures, there are 612 roadblocks and obstructions, a rise of more than 60 percent compared to their number when the freedom of access and movement agreement was signed in 2005.

Palestinian sources said the PA was acting to bring about a denunciation of Israel at both the conference and the Quartet's meeting. The conference's closing statement is also expected to praise the PA for beginning to implement Prime Minister Salam Fayyad's reforms.

Sources in Jerusalem on Thursday said that the Quartet is expected to support Russia's plan to convene an international peace conference in Moscow. Russian Foreign Minister Sergei Lavrov has been making efforts to bring about this event, with the encouragement of PA chairman Mahmoud Abbas.

Palestinian sources say Abbas believes that such a conference in Moscow would force Israel to speed up the peace talks, or alternatively, lead to harsh criticism of Israel if it refuses.

However, a senior PA official blasted Russia's conduct. He said the Russians have been playing a double role, wishing to mediate between Hamas and Fatah while at the same time keeping open channels to Iran, Syria, Hezbollah and Hamas, so as to act as a counterbalance to the United States.

British Middle East envoy Michael Williams said yesterday that Israel's failure to remove West Bank roadblocks is a source of "grave concern."

However, he said a balance must be struck between removing the roadblocks, which is essential for the Palestinian economy's growth, and Israel's security needs. Fayyad is expected to call on the donor states to pressure Israel to remove the roadblocks.

Conference host Britain said it intended to ensure that the donor states meet their undertaking to contribute $7.7 billion to building economic institutions in the Palestinian Authority, as they resolved to do at the Paris conference in December.

Foreign Minister Tzipi Livni, who will represent Israel in London, is expected to meet her Egyptian counterpart Aboul Gheit there. The two, who have not met since their highly publicized confrontation in December over arms smuggling from Sinai into Gaza, are expected to discuss the peace process between Israel and the PA and the situation in the Gaza Strip.

Livni is also due to discuss the Iranian nuclear program and the peace talks with Ban and with British Prime Minister Gordon Brown. She is also scheduled to meet Foreign Secretary David Miliband, and Shadow Foreign Secretary William Hague.