SHARM EL-SHEIKH, Egypt (AFP) - Top world diplomats appealed on Monday for rival Palestinian factions to reconcile, saying that it is vital if the hobbled Middle East peace process is to get back on track. The plea, made at a donors' conference in Egypt, came despite the fact that a Palestinian unity government including Hamas would prove a highly delicate issue for Washington. Leaders of the Middle East Quartet grouping the European Union, Russia, the United Nations and the United States met for informal talks on the sidelines of the Gaza aid gathering in the Red Sea resort of Sharm El-Sheikh. "We want to strengthen the Palestinian Authority" of President Mahmud Abbas, a senior US official quoted her as saying. The US official quoted Obama's new Middle East envoy George Mitchell, who helped to broker peace in Northern Ireland, as saying: "We hope that there will be Palestinian unity in a way that will advance the two states solution." "We want to figure out how to promote Palestinian reconciliation," the US official quoted UN Secretary General Ban Ki-moon as saying, while Russian Foreign Minister Sergei Lavrov urged the movement to rejoin the Palestinian fold. "It is important that we encourage Hamas to accept the PLO platform," Lavrov said of the main Palestine Liberation Organisation umbrella group, the official said. Tony Blair, Britain's former prime minister and now the Quartet's special Middle East envoy, was quoted as saying that "the decisions of the next few weeks will determine how we move forward on the next few years." After the Quartet meeting, which ended without a formal communiquT being issued, EU External Relations Commissioner Benita Ferrero-Waldner urged the US administration to take the lead in efforts to bring peace to the Middle East. "We are in favour of reconciliation behind President Mahmud Abbas," she said. Foreign Minister Ahmed Abul Gheit of conference host Egypt said Cairo expects wide international support for a Palestinian unity government. Meanwhile, US Secretary of State Hillary Clinton called on Monday for all sides in the Gaza conflict to work towards a durable ceasefire and condemned continued rocket attacks on Israel. "I am troubled by the continuing rocket attacks coming out of Gaza," Clinton said at a press conference following an international donor conference. "We call upon all (parties) to move toward a durable ceasefire," she said. "But it is very difficult for any country to just sit and take rockets falling on its people, that is the crux of the Israeli problem. How are they supposed to respond when they continue to have that kind of attack." On the Israeli-Palestinian peace process, Clinton said: "The US is prepared to engage in aggressive diplomacy with all sides in pursuit of a comprehensive settlement that brings peace and security to Israel and its Arab neighbours." Clinton is due to leave Egypt for talks with Israeli leaders on Tuesday on Middle East peace efforts.