A senior Palestinian official said Thursday he will ask visiting U.S. envoys to help block the expansion of the largest Jewish settlement in the West Bank, warning that the planned construction would cut off east Al-Quds city _ the Palestinians' intended capital _ from territory they seek for a future state. The envoys, National Security Council official Elliott Abrams and David Welch, assistant secretary of state for the Near East, asked Israeli Prime Minister Ariel Sharon on Wednesday about the planned expansion of the Maaleh Adumim settlement, located five kilometers (three miles) east of Al-Quds city. Israel plans to build 3,500 more homes in Maaleh Adumim, driving a wedge between east Al-Quds city and the West Bank. Saeb Erekat, the chief Palestinian negotiator, said the Maaleh Adumim expansion would top his agenda talks later Thursday with Abrams and Welch. "The most important thing at this stage is to ... stop settlement activities," Erekat said. U.S. State Department officials have said the envoys were seeking clarifications from Israel on the expansion plans _ language that implies criticism, according to a report of the Associated Press.