The Palestinian Authority is coming under increasing pressure ­ from Israel and the international community ­to back down from its threat to unilaterally declare a state without first concluding a peace agreement with Israel.

On Monday evening, The United States on Monday reaffirmed its support for the resolution of the Israeli-Palestinian conflict through negotiations, in its first official response to the Palestinian plan.

"It is our strong belief and conviction that the best means to achieve the common goal of a contiguous and viable Palestine is through negotiations between the parties," the U.S. State Department said in a statement.

U.S. senators visiting Israel said earlier in the day that on Monday that Washington would veto a Palestinian declaration of statehood in the United Nations Security Council.

The idea of seeking UN intervention has been gaining steam in the Arab world as the impasse in peacemaking drags on. The Palestinians seek a state in the West Bank, Gaza Strip and east Jerusalem, territories Israel captured in 1967.

The senators said the threat by Palestinian officials to take the issue to a UN resolution was a waste of time and would go nowhere. They urged Arab states to stop it.

"It would be D.O.A. - dead on arrival," Democratic Party Senator Ted Kaufman (DE) told a news conference in Jerusalem. "It's a waste of time."

Senator Joseph Lieberman (CT), an independent, said "an essentially unilateral" declaration of statehood was the one thing that would not move the stalled peace process forward."

Meanwhile, the Palestinians asked the European Union on Monday to back their plan.

"We will seek the support of all members of the international community," Saeb Erekat, a top adviser to Palestinian President Mahmoud Abbas, told reporters in Ramallah. Besides the EU, they also plan to seek U.S. approval, Erekat said.

EU foreign ministers will discuss the Arab-backed proposal at their regularly scheduled meeting on Tuesday, said Petra Dachtler, an adviser to the EU's special Middle East envoy, Marc Otte. Because the idea has only been floated recently, the EU has yet to formulate an opinion, she said.

The EU is not on the Security Council, but EU members France and Britain are permanent council members that wield veto power.

The plan appears to be largely symbolic, given that the U.S., Israel's chief ally, would likely veto such an initiative at the United Nations. It also would not remove the 500,000 Israelis living in West Bank settlements and east Jerusalem neighborhoods.

The move, however, reflects growing Palestinian frustration with the deadlock in peace efforts. Palestinian officials say they hope international endorsement would force Israel to recognize a future Palestine's borders based on the pre-1967 lines.

Earlier Monday, Hamas rejected the PA initiative, saying true independence required the complete cessation of Israeli occupation.

The Islamist militant group pointed out that a unilateral declaration of statehood had already been made by the late Palestinian leader Yasser Arafat in 1988.

If it had to be done again, Hamas spokesman Salah Bardweel said on Monday, "why not declare a Palestinian state from the sea [Mediterranean] to the river [of Jordan]" rather than in the West Bank and Gaza only.

The declaration proposed by Erekat would have no meaning and was merely an attempt by the rival Palestinian camp of President Mahmoud Abbas to pretend it had an alternative to faltering peace negotiations, other than armed struggle, said Bardweel.

"This move is not a meaningful declaration. It simply aims at escaping the benefits of resistance against the occupation," he said. "Instead of threatening to unilaterally declare a Palestinian state to be established in the air, we should work on liberating the occupied territories and end the current internal [Palestinian] division."

Declaring a state "in the air on 20 per cent of the Palestinian land, which would be rejected by the world," was not the solution, he argued. Rather, Palestinians should focus on their own "ability to liberate the land."

Industry and Trade Minister Benjamin Ben Eliezer (Labor) said Monday that his center-left party would pull out of the government if it carried through with right-wing calls to annex more West Bank settlements in response to a unilateral Palestinian declaration of independence.

"The Labor party cannot continued to sit in this government if it decides to annex settlements," said Ben Eliezer. Negotiating with the Palestinians is the only viable option, he said, dismissing both Israeli and Palestinian threats for unilateral moves.

"In my opinion this whole thing about annexation is just words. I think the Palestinian threat also is just words. A ping-pong of declarations will get us nowhere, the only way forward is to bring the sides together for negotiations," he told Army Radio.

Prime Minister Benjamin Netanyahu responded to Erekat's suggestion by saying that Israel would make unilateral moves of its own should the Palestinians make good on its threat. He did not elaborate on what that might mean.

National Infrastructure Minister Uzi Landau and Transportation Minister Yisrael Katz backed up the prime minister's call by detailing what they believed such unilateral motions would mean:

"We must be clear and tell them that, if that's the route they choose to take, any unilateral declaration on their part will be countered by declaring our sovereignty on all 'C' Areas," Landau said, referring to those which, according to the Oslo Accord, are in full Israeli civilian and military control.

"I think it is an outrage," Landau added of the possibility of a unilateral declaration of independence.

"We've been seeing a series of Palestinian attempts in various area and this is one of them. It is a hostile proposition, one surely meant to erode any chances of continuing negotiations," Landau said.

Environment Minister Gilad Erdan told Army Radio: "If the Palestinians take such a unilateral line, Israel should also consider ... passing a law to annex some of the settlements."

Other options of sanctions were also available, he said. "Everything is open ... it could begin at stopping the transfer of money that the Israeli government currently transfers to the Palestinian Authority," he told the radio, referring to tax payments Israel collects on the Authority's behalf under interim peace deals.

Erdan said Israel might also consider tightening recently loosened travel restrictions on Palestinians in the West Bank.

Foreign Minister Avigdor Lieberman responded to the Palestinian Authority's suggestion by saying that Israel would see unilateral moves of the kind as an explicit violation of past agreements.

"Any one-sided Palestinian move will be met with steps of our own." he said. "Whoever makes unilateral policy with complete disregard for past accords will get the same from us."

"Breach of accords will not go unanswered," he said.

According to Lieberman, Israel could not count on the Americans to veto any such Palestinian request to the UN Security Council.

"Nothing is certain when it comes to an American veto, but I think the Americans understand that these policies bury any chance of reaching peace, and I think that the U.S. would also find it uncomfortable to have to deal at the Security Council with recognition of a Palestinian state.