Direct talks with Israel will not resume unless it halts the building of Jewish settlements on occupied land, the Palestinian leadership said on Saturday. U.S.-backed peace talks, launched a month ago in Washington, were plunged into crisis this week by the end of a 10-month Israeli moratorium on new settlement building in the West Bank. Israel has said it will not extend the freeze. "The resumption of talks requires tangible steps, the first of them a freeze on settlements," Yasser Abed Rabbo, a senior Palestine Liberation Organization (PLO) official, said after a meeting of the body's executive committee in Ramallah. Israeli Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas have held three rounds of face-to-face negotiations since Sept. 2. "The Palestinian leadership holds Israel responsible for obstructing the negotiations," said Abed Rabbo. Abbas, head of the PLO, chaired the meeting, Reuters reported. U.S. envoy George Mitchell, who met Arab League head Amr Moussa and intelligence chief Omar Suleiman in Cairo on Saturday, said the United States remained committed to a two-state solution despite challenges. "Peace in the region and an independent and viable state for the Palestinian people will be realistically achieved through direct negotiations," Mitchell told reporters. "This is a difficult process ... We know there have been and will be many more obstacles, but we must work to overcome the challenges and we are doing so," he said. Asked about possible options to resolve the impasse, Moussa said there were solutions but declined to elaborate ahead of an Arab League summit in Libya on Oct 8.