The Quartet made the appeal at the end of a top-level meeting hosted by UN Secretary-general Ban Ki-moon at UN Headquarters in New York. The Quartet groups the United Nations, the European Union (EU), Russia and the United States.

The Quartet statement called on the Palestinians to continue their efforts to reform the security services and dismantle the infrastructure of terrorism.

Meanwhile, the group called on Israel to freeze all settlement activities, which have a negative impact on the negotiating environment and on Palestinian economic recovery, and to address the growing threat of settler extremism, according to the statement.

"The Quartet expressed its considered view that the bilateral negotiations process launched at Annapolis (in Maryland last year) is irreversible and that these negotiations should be intensified in order to put an end to the conflict and to establish as soon as possible the state of Palestine, living side by side in peace and security with Israel," the statement said.

"The Quartet affirmed that a final treaty and a lasting peace will be reached through simultaneous and mutually reinforcing efforts on three tracks: negotiations; building the institutions of a Palestinian state, including facilitating economic development through an improvement of conditions on the ground; and implementation of the parties' obligations under the Roadmap, as stated in the Annapolis Joint Understanding," the statement said.

The partners have long championed the Roadmap, which embodies the two-State solution, first set for achievement by the end of 2005. At the Annapolis meeting in the Unite States last year, participants set the hoped-for target for the end of this year, and UN officials have voiced regret that this, too, has proved impractical.

Turning to the Gaza Strip where Hamas, which does not recognize Israel's right to exist, had seized control from the West Bank-based Palestinian Authority (PA) in 2006, the Quartet called for a continuation of the calm between Gaza and southern Israel, due to expire at the end of the week, that has reduced violence between Israel and Palestinians there.

A lasting solution to the situation in Gaza can only be achieved through peaceful means and all Palestinians must commit themselves to non-violence, recognition of Israel, and acceptance of previous agreements and obligations, the statement said, adding that restoring Palestinian unity based on "the legitimate and internationally recognized" authority of the PA would be an important factor in this process.

Meanwhile, the Quartet condemned "indiscriminate attacks" on Israel from Gaza and called for an immediate cessation of violence. It also stated its "acute concern" at the recent increase in Israeli closures of crossing points in response to violence, noting they had cut basic commodities and humanitarian supplies, worsening the economic and humanitarian situation there.

The Office of the UN Special Coordinator for the Middle East Peace Process (UNSCO) reported yesterday that the Gaza power plant, which supplies a portion of the territory's needs, has been turned off by the company in charge there. The decision was taken following the closure of all goods crossings on Sunday.

A series of rolling blackouts have been occurring through out the Gaza Strip since Sunday evening -- ranging from 12 hours a day in some areas to 4 hours a day in others.

The UNSCO also reported that 81 truckloads of materials did pass from Israel into Gaza yesterday, including 20 truckloads for humanitarian aid agencies that included flour, milk and medicine.

"The Quartet emphasized that the provision of humanitarian supplies, including food, fuel, pharmaceutical, water and sewage maintenance items, to the people in Gaza must be assured continuously," the statement said. "The Quartet also reiterated its previous call for Israel to allow into Gaza sufficient materials to facilitate the resumption of stalled UN and other donor projects."

It also called for the immediate and unconditional release of Israeli Corporal Gilad Shalit, whose seizure in Israel by Palestinian militants from Gaza over two years ago unleashed a new wave of violence.

"The Quartet viewed the successful deployment of the Palestinian security services to Hebron as the most recent demonstration of the substantial progress that has been made since Annapolis," it added.

Attending the meeting with Ban were EU High Representative for Common Foreign and Security Policy Javier Solana and European Commissioner for External Relations Benita Ferrero-Waldner, Russian Foreign Minister Sergei Lavrov, and US Secretary of State Condoleezza Rice.

Speaking to reporters after the meeting, Ban thanked the outgoing administration of President George W. Bush for its efforts to advance the Israeli-Palestinian negotiations. "These efforts have been tireless and are continuing. Very important progress is underway," he said.

"In this respect we look forward to working closely from the outset with the administration of President-elect (Barack) Obama to achieve the goal of the two-State solution and comprehensive Arab-Israeli peace," he said.

After the joint press conference, Quartet members met with representatives of the League of Arab States, invited by the UN chief to attend the talks alongside Quartet partners.

The meeting was convened as the UN Security Council met behind closed doors to discuss a draft resolution on the Middle East, which is to be adopted at a ministerial meeting of the 15-nation Council.

The draft resolution, billed as a joint US-Russian initiative, aims to encourage the successful implementation of a two-State solution to the Palestinian-Israeli conflict, diplomatic sources said.

The Quartet has called for the establishment of an independent Palestinian state living in peace together with Israel. Various security and political steps have to be carried out before the two-State solution is achieved under what is known as a roadmap to end the lengthy conflict between Israel and Palestine.