A leading Hamas official in Gaza says the radical Islamist group will take over the West Bank if Israel pulls out.

Speaking at a rally in northern Gaza on Friday, Mahmoud Zahar, a former foreign minister in the Palestinian unity government, declared, "Israel thinks Fatah in the West Bank is there to serve it, but we will take over the West Bank the way we took over Gaza.

"The residents of the West Bank must learn the lesson of what happened in the Gaza Strip. Anyone who comes into the Gaza Strip will leave in pieces," he said, threatening any invader, whether Palestinian or Israeli.

The statements by Zahar, a known firebrand, contradict those made by former Palestinian prime minister Ismail Haniyeh a week earlier. Haniyeh said Hamas had no plans for a violent takeover of the West Bank.

During the rally, Zahar also warned the Palestinian negotiating team against any concessions on the core issues at the Annapolis summit. "Whoever relinquishes a grain of Palestinian land severs an organ from himself," he said. "Palestinian land is one - from Rafah in the south to Rosh Hanikra in the north, from the Jordan river in the east to the Mediterranean sea in the west."

Last week, Haniyeh said, "All the reports that we want to repeat what happened in Gaza in the West Bank are baseless .... This is not going to happen."

Meanwhile, senior Palestinian sources say Israel is delaying progress in the negotiations in preparation for Annapolis, and is not pushing ahead with an American proposal to create a tripartite committee that would supervise the implementation of the first part of the road map.

Israel has conditioned any progress in the the peace process on the implementation of the first stage of the road map, which includes Palestinian counterterrorism and the dismantling of illegal outposts.