WASHINGTON - The United States must back a Palestinian bid for UN recognition of statehood or risk becoming "toxic" in the Arab world and forcing a split with ally Saudi Arabia, a top Saudi diplomat warned Monday.

If Washington imposes its veto when the Palestinians seek to become the 194th member state of the United Nations then "Saudi Arabia would no longer be able to cooperate with America in the same way it historically has," former Saudi ambassador to the United States, Prince Turki al-Faisal wrote.

He warned in a commentary in the The New York Times that a US veto would see American influence decline, "Israeli security undermined and Iran will be empowered, increasing the chances of another war in the region."

"The 'special relationship' between Saudi Arabia and the United States would increasingly be seen as toxic by the vast majority of Arabs and Muslims, who demand justice for the Palestinian people."

Saudi leaders would be forced therefore to "adopt a more independent and assertive regional policy," he warned, pointing to such incidents as Riyadh's recent military intervention in Bahrain.

Frustrated by the lack of progress in the Middle East talks, the Palestinians have insisted they will go ahead with a UN membership bid despite the US veto threat.

President Mahmud Abbas is expected to submit a formal request to the UN Secretary General Ban Ki-moon to accept the state of Palestine as a member on the sidelines of the UN General Assembly on September 20.

Prince Turki, a former Saudi intelligence chief, argued Palestinian statehood would allow the stalled peace process to move forward and replace it "with a new paradigm based on state-to-state negotiations."

"The only losers in this scenario would be Syria and Iran, pariah states that have worked tirelessly -- through their support of Hamas and Hezbollah -- to undermine the peace process."

He argued that the embattled regime of Syrian President Bashar al-Assad, rocked by months of pro-democracy opposition protests, was about to fall providing "a rare strategic opportunity to weaken Iran" which would find it more difficult to "foment discord in the Arab world."

"But this opportunity will be squandered if the Obama administration's actions at the United Nations force a deep split between our countries."

The New York Times in an searing editorial also sharply criticized the United States, Israel and Europe for showing "insufficient urgency or boldness in trying to find a compromise solution."

The United States "made a listless effort" last week to persuade the Palestinians to drop their UN bid in favor of new peace talks, which have been stalled since September 2010, the Times said.

It added that it was "astonishing that this late in the game, America and Europe remain divided over some aspects of a proposal for peace talks."

It put the "greater onus" for the lack of progress on Israeli Prime Minister Benjamin Netanyahu "who has used any excuse to thwart peace efforts."

But the Times added US President Barack Obama "needs to show firmer leadership in pressing Mr. Netanyahu and Mr. Abbas to resume talks."