A Palestinian official said on Monday the United States had yet to give adequate answers to Palestinian queries on a proposal for indirect negotiations with Israel.
Palestinian President Mahmoud Abbas, facing U.S. and Israeli calls for an immediate resumption of peace talks, had asked the United States to clarify its proposal for indirect negotiations.
U.S. Secretary of State Hillary Clinton said last week she hoped talks would start "shortly".
But Mohammed Dahlan, senior official in Abbas's Fatah party, said the U.S. clarifications received so far were not enough.
"I can say that up until now, the American responses to the Palestinian questions have not been enough," he said.
Abbas has demanded a full halt to Israeli settlement building in the West Bank and East Jerusalem, occupied by Israel since 1967, before any resumption of negotiations.
Israel rejected his call, instead imposing a limited, temporary "freeze" on settlement expansion in the West Bank, but excluding East Jerusalem, which Israel considers part of what it calls its indivisible capital.
Palestinian officials have said the latest U.S. efforts to revive the peace process have been damaged by recent Israeli moves including a decision to include West Bank religious sites in a Jewish heritage plan.
Palestinians see the plan, announced last week, as a move to strengthen Israeli control over land where they hope to found their state. Israel says the aim is to preserve the sites, not to impinge on Muslim worship.
The Ramallah-based Palestinian cabinet convened in the city of Hebron on Monday in protest against the plan.
"CYCLE OF VIOLENCE"
The cabinet headed by Prime Minister Salam Fayyad listed the project among Israeli "provocations" including plans for 600 new homes on occupied land in East Jerusalem, which the Palestinians want as their capital.
Israel's moves, the cabinet said in a statement, "threaten to drag the region to a new cycle of violence and destroy the state of stability which the Palestinian Authority is working to establish".
The U.S. State Department, addressing the Israeli plan for 600 new homes in East Jerusalem, urged both sides to refrain from unilateral actions that "undermine trust" and efforts to restart the peace talks.
"We have relayed our strong concerns to the government of Israel that this kind of activity, particularly as we try to relaunch meaningful negotiations, is counterproductive and undermines trust between the parties," State Department spokesman P.J. Crowley said.
Palestinian anger over the heritage project has already ignited violence. Palestinian youths and Israeli soldiers clashed in Hebron over several days last week.
They also clashed at Jerusalem's most sensitive holy site on Sunday. A gunman wounded an Israeli security guard on Monday near an apartment block that houses Jewish settlers in an area of East Jerusalem.
The West Bank was a main front in an armed Palestinian uprising against Israel earlier this decade. Israeli officials have praised the current stability, in part attributed to Palestinian security forces retooled with EU and U.S. backing.
The Hamas Islamist group, which controls the Gaza Strip and is hostile to Israel, has called on Palestinians to respond to the Israeli heritage plan by staging a new uprising in the West Bank.
The cabinet called on the international Quartet of Middle East negotiators -- the United States, the European Union, the United Nations and Russia -- "to halt the Israeli policy which is destroying the future of security and peace in the region".
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