The Palestinians say that if a peace treaty with Israel isn’t reached by September their first choice is to go to the U.N. Security Council with such strong support and arguments that it would recommend admission of Palestine as a new member of the United Nations.

That would require convincing the U.S., Israel’s ally, not to veto a resolution supporting membership for an independent Palestinian state, which won’t be easy.

But Riyad Mansour, the top Palestinian diplomat at the U.N., said in an interview with The Associated Press that there are other options to achieve the goal through the U.N.

He said September looms large for the Palestinians because “there are so many things that will converge.”

First, Israel and the Palestinians agreed on President Barack Obama’s target of September 2011 for a peace agreement, a date endorsed by the European Union and much of the world. Second, the two-year program to build the infrastructure of a Palestinian state will be complete, and third, the Palestinians hope two-thirds of the 192 U.N. member states will have recognized Palestine as an independent state, Mansour said.

Obama announced in September 2010, as U.S.-brokered direct Israeli-Palestinian negotiations resumed, that a peace treaty should be signed in a year, but those talks collapsed weeks later after Israel ended its freeze on building settlements.

The Palestinians insist they will not resume peace talks until Israel stops building settlements in the West Bank and east Jerusalem — lands it captured in the 1967 Middle East war and which the Palestinians want for their future state. Israel maintains that the Palestinians should not be setting conditions for talks and that settlements didn’t stop them negotiating in the past.

“Our preference what should happen in September is to have a peace treaty with the Israelis to end the occupation to allow for our independence and our membership in the United Nations,” Mansour said.

The U.S. has been heading efforts to restart negotiations but Mansour said the Palestinians want the Quartet — the mediating group consisting of the U.S., U.N., European Union and Russia — to take the lead.

Mansour expressed regret that the U.S. blocked a Quartet meeting tentatively scheduled for last Friday in Berlin to discuss, and hopefully endorse, the outlines of a peace settlement proposed by Britain, France and Germany. A U.S. official said a Quartet meeting wouldn’t produce anything that would help restart direct talks.

But Mansour said Palestinian leaders “indicated willingness to go back to negotiations” if the Quartet agreed on the proposal by the three European countries.

It calls for an immediate halt to settlement activity, a solution to the question of Palestinian refugees, and agreement on the status of Jerusalem as the future capital of both countries and on borders before the 1967 Mideast war, with approved land swaps. It also called for security arrangements that respect Palestinian sovereignty and protect Israel’s security and prevent a resurgence of terrorism.

“We’re trying our best to open doors for negotiations,” Mansour said in the interview late Thursday. “The Israelis are choosing settlements over peace.”

Israeli Foreign Ministry spokesman Yigal Palmor said “the sooner the Palestinians agree to resume peace talks, the sooner we will all be able to take steps that will bring us closer to peace.”

The goal of establishing a Palestinian state, living in peace with Israel, “can only be achieved through dialogue and negotiations — there is simply no other way,” Palmor said. “Unilateral measures go exactly the opposite way.”

But Mansour said that if there is no peace treaty by September, “for whatever reasons, then we are not going to be hostage to the position of Israel, nor will we accept that nothing can be done until the Israelis are ready and willing.”

For the last two years, he said, the Palestinians have been preparing for independence and on Thursday they won an important endorsement when a meeting of key donor states in Brussels said that the institutions developed by the Palestinian Authority are now “above the threshold for a functioning state.”

The donors, who give the Palestinians hundreds of millions of dollars in aid each year, cited reports prepared by the World Bank, the U.N. and the International Monetary Fund.

In addition, Mansour said, Palestine has been recognized as an independent state by 112 countries. Possible recognition by six others is being examined, he said, and “hopefully by September 2011 we will have 130, maybe 140 countries recognizing the state of Palestine.”

That is important because U.N. membership not only requires a recommendation from the Security Council but approval by two-thirds of the General Assembly, or 128 countries.

“This is the end game,” Mansour said — the more countries the Palestinians have on their side, the more they can pursue independence, “whether in the Security Council or in the General Assembly or combined.”

If a U.S. veto looks certain in the Security Council, there’s the option of going before the General Assembly, where there is no veto but resolutions are nonbinding.

Mansour said that among other options is a General Assembly resolution similar to that of 1947 that called for Palestine to be divided into Jewish and Arab states. Another possibility advanced by some is “Uniting for Peace,” a General Assembly resolution that allows it to take action if it believes the Security Council has failed to head off a threat to world peace and security.

But that option would be hard to implement because it would require proving that denying the Palestinians U.N. membership.