A pessimistic U.S. secretary of state will meet Israeli and Palestinian leaders Monday for what are billed as make-or-break talks to try to revive the stalled Middle East peace process.

The London meetings "are decisive for the future of the peace process," the senior Palestinian representative in Britain, Afif Safieh, said Sunday. The negotiations are teetering between "the desirable breakthrough and the possible breakdown."The United States has warned that it may abandon its mediation if the 14-month stalemate over Israeli withdrawal from the West Bank continues. And Palestinian leader Yasser Arafat reiterated that he will declare statehood in May 1999, regardless of whether there is a deal with Israel.

Secretary of State Madeleine Albright has already won Palestinian approval for an American initiative that calls for Israel to hand over 13 percent of the West Bank. The phased Israeli withdrawal is to be linked to a Palestinian crackdown on Islamic militants.

But Israeli Prime Minister Benjamin Netanyahu has refused to accept the proposal despite intensive U.S. diplomatic efforts, including a meeting Sunday with Vice President Al Gore.

In a gloomy forecast, State Department spokesman James P. Rubin said Sunday the Gore-Netanyahu talks failed to resolve "any of the big issues" and "the gaps have not been closed."

Top Netanyahu aide David Bar-Illan was similarly pessimistic: "There will be some progress, but anybody who expects a dramatic breakthrough will be disappointed."

Israel has said it will hand over 9 percent of the West Bank, and some reports have said Netanyahu is willing to offer up to 11 percent. But the Palestinians say 13 percent is their absolute minimum.

"The success of the talks in London will depend on Netanyahu's actions, because the problem does not lie anywhere else," Arafat said in Gaza before leaving for Britain.

"His policy is to try to gain time," the Palestinian leader told London's Sunday Observer earlier. Safieh, the Palestinian diplomat, called Netanyahu "a pyromaniac on a powder keg."

"I believe the Americans are seeing him increasingly not as a strategic asset in the Middle East, but as a strategic liability," he told Sky Television.

Safieh said Netanyahu's vision of a future Palestine was of tiny enclaves, isolated from each other, "that are totally unviable and totally humiliated and have no ingredients for economic takeoff."

Israel promised in January 1997 to carry out three troop withdrawals from the West Bank, with the scope of each to be decided by Israel alone. The Palestinians had hoped that would give them control of at least 60 percent of the land.

"So we believe the American proposal of 13 percent is really the minimum that could be offered to keep the machinery going on," Safieh said.

As Albright headed for London on Saturday, Rubin warned there would be "grave dangers" if the stalemate continues.

Prime Minister Tony Blair is expected to meet Netanyahu and then Arafat on Monday before they hold separate talks with Albright.

Safieh said that if there is a possibility of a breakthrough, the Palestinian and Israeli leaders might meet together with Albright - and maybe with a European representative as well. That presumably would be Blair or British Foreign Secretary Robin Cook since Britain currently holds the rotating presidency of the European Union.

The London meeting will take place exactly one year before the May 4, 1999, deadline for the completion of Middle East peace negotiations set in the 1993 Oslo peace accords.

All sides know the peace process cannot drift indefinitely.

Arafat reiterated to The Sunday Times that next May he will announce an independent Palestinian state.

"My decision is final," he said.

Safieh added: "I believe Palestinian statehood is not only our right but I also believe it's a Jewish responsibility."

Netanyahu has hinted he would retaliate by annexing some of the West Bank. And with both sides freed of restraints imposed by the peace accords, many fear renewed violence.