WASHINGTON (JTA) — Iran’s failure to meet a Nov. 24 deadline for a nuclear deal would “drastically” reduce the chances for an agreement, a top White House official said.

Philip Gordon, the Middle East counselor on the National Security Council, told JTA on Monday that gaps remain in the talks between Iran and the major powers because Iran wants to preserve aspects of its nuclear program that are unacceptable.

“There are gaps because they are trying to preserve some things that we are simply not prepared to accommodate,” Gordon said, without elaborating. “It is not however impossible to close those gaps. What we are focused on is getting it done by November 24th — anything after that dramatically reduces the chances for a deal.”

Reports have suggested in recent weeks that the sides may seek to extend the talks, which have been underway since January and which were already extended once, in July.

Top lawmakers in the incoming GOP-led Senate have said that they will advance new sanctions legislation if talks are extended beyond the deadline, and want to approve any deal.

Asked about the prospects of such legislation, Gordon cautioned against any actions that would disrupt the close coordination between the United States and its five partners in the talks, Russia, China, Britain, France and Germany.

“So long as we are working with our partners and demonstrating that the problem here is that Iran is not willing to demonstrate the peaceful nature of its program,” the pressure on Iran to strike a deal will continue, he said. “If we were to insist on things that our partners didn’t agree with we might have a problem.”

Citing that need for unity with other major powers, Gordon suggested that Israel’s demand that Iran completely dismantle its nuclear program was unrealistic, although he said the United States was sympathetic to it.

Instead, he said, with increased inspections, the dismantling of a plutonium reactor and the substantive reduction of Iran’s uranium enrichment capacity, the United States hoped to expand Iran’s breakout time to a nuclear weapon to a year, which would give the United States more time to stop it.

“We could in these talks take the view that the only acceptable outcome to us is zero centrifuges,” he said.

“But if the result of that was Iran saying, ‘Well, on that basis, no deal, tomorrow we’re going to not only start enriching at 20 percent, we’re going to install the 10,000 centrifuges that weren’t installed before, we’re going to restart the Arak (plutonium) reactor, then we would have the clock ticking toward a real crisis, a real breakout capacity and we would reduced to very poor options, which would be letting Iran have a nuclear weapon which we’re obviously not going to do or using military force which has all sorts of other consequences and would only set the program back a certain amount of time.”

Regarding the recent escalation in violence between Arabs and Jews in Israel and the West Bank, Gordon said the Obama administration was urging the Israeli and Palestinian leaders to communicate and to calm tensions.

Asked what the White House’s specific message was to Israeli Prime Minister Benjamin Netanyahu and Palestinian Authority President Mahmoud Abbas, Gordon said: “Anyone who is not urging calm and non-violence and a return to the status quo ruins the risk that it can be a very explosive situation.”

Gordon spoke to JTA at a meet the press opportunity at this year’s Jewish Federations of North America General Assembly.