Former senior U.S. officials have sent President Barack Obama a letter urging him to refrain from vetoing a United Nations Security Council resolution condemning Israeli settlements in the West Bank.

The letter, signed by a former U.S. secretary of defense, a number of former assistant secretaries of state and U.S. ambassadors, calls on Obama to instruct the U.S. envoy to the UN to "vote yes" on the resolution condemning Israeli settlements.

"The time has come for a clear signal from the Unites States to the parties and to the broader international community that the United States can and will approach the conflict with the objectivity, consistency and respect for international law required if it is to play a constructive role in the conflict's resolution," the letter urged.

The authors of the letter said they recognize that the UNSC resolution will not resolve the issue of settlements, but said it is "an appropriate venue for addressing these issues."

They went on to remind Obama of his 2009 Cairo speech in which he said that the U.S. does not accept the legitimacy of continued Israeli settlements and urged Israel to stop its settlement activity.

"If the proposed resolution is consistent with existing and established U.S. policies, then deploying a veto would severely undermine U.S. credibility and interests, placing us firmly outside of the international consensus, and further diminishing our ability to mediate this conflict," the U.S. officials wrote.

Moreover, they warned Obama that a veto on such a resolution would diminish the overall "seriousness" of the U.S. as a "guarantor of international law and international legitimacy."

Among the signatories of the letter was Frank Carlucci, former U.S. Secretary of Defense; Richard Murphy, former Assistant Secretary of State and former ambassador to Syria and Saudi Arabia; Thomas Pickering, former Undersecretary of State and former ambassador to Israel and the United Nations; Everett Ellis Briggs, former special adviser to President George H. W. Bush; and former Assistant Secretary of State Allen Holmes.

Diplomats say that the point of the draft resolution condemning settlement building is to highlight Washington's isolated position on the Security Council, show the Palestinian population that the Palestinian Authority is taking action, and to pressure Israel and the United States on the settlement issue.

Council diplomats said privately that the 15-nation panel was unlikely to take any action on the draft resolution in the near future - if at all - because of the likely veto.

It has nearly 120 co-sponsors, exclusively Arab and other non-aligned nations. UN diplomats said that the draft would probably receive 14 votes in favor and the one veto if put to an immediate vote.

The draft says that "Israeli settlements established in the Palestinian Territory occupied since 1967, including East Jerusalem, are illegal and constitute a major obstacle to the achievement of a just, lasting and comprehensive peace."

Intensive U.S. diplomatic efforts to revive direct peace talks between Prime Minister Benjamin Netanyahu and Palestinian President Mahmoud Abbas collapsed last year after Israel failed to extend a 10-month freeze on West Bank settlement construction.