Nuclear talks in Geneva
Nuclear talks in Geneva Reuters

U.S. President Barack Obama signaled Wednesday that talks with Iran on its nuclear program may need to extend beyond a weekend deadline, saying negotiations have shown a "credible way forward," according to AFP.

Obama said he was consulting with Congress - where there is strong criticism of his quest for a diplomatic deal with Iran - as negotiators meet in Vienna ahead of Sunday's expiration of a temporary deal.

"It's clear to me that we have made real progress in several areas and that we have a credible way forward. But as we approach a deadline under the interim deal, there are still significant gaps between the international community and Iran and we have more work to do," Obama was quoted as having told reporters.

"So over the next few days, we'll continue consulting with Congress and our team will continue discussions with Iran and our partners as we determine whether additional time is necessary to extend our negotiations,” he added.

Iran has "met its commitments" under the interim agreement, including halting progress of its nuclear program and allowing more inspections, Obama said.

White House spokesman Josh Earnest earlier appeared to prepare the political ground for an extension of talks, saying that many people had been "pretty skeptical" about Iran but found "legitimate discussion and constructive engagement."

"It is clear that their track record over the last six months, I think many people would acknowledge, has been surprisingly favorable," Earnest said.

The comments come a day after Iran’s Foreign Minister, Mohammad Javad Zarif, suggested that the six world powers are leaning towards extending nuclear talks with Tehran beyond the July 20 deadline.

Iran has toughened its positions over the past week. Its Supreme Leader, Ayatollah Ali Khamenei, said Iran "needs" 19 times more nuclear centrifuges than the amount being offered by world powers.

Iranian nuclear agency head Ali Akbar Salehi echoed Khamenei’s remarks a day later, saying Iran wants to greatly expand its uranium enrichment program despite Western fears that it could be used to make atomic arms.

Kerry and other Western leaders said on Sunday that "significant differences" remain between the sides.

Israeli Prime Minister Binyamin Netanyahu has led criticism of the nuclear deal, accusing Iran of insincerity and not ruling out an attack.

U.S. lawmakers, who are widely supportive of Israel, have threatened to ramp up sanctions without a rigorous agreement.

Senator Robert Menendez, a member of Obama's Democratic Party who chairs the Senate Foreign Relations Committee, has called for an accord that dismantles Iran's nuclear program in a way that is verifiable for 20 to 30 years.

"The fact is Iran's nuclear aspirations have been a long and deliberate process. They did not materialize overnight, and they will not end simply with a good word and a handshake We need verification," Menendez said Tuesday, according to AFP.

"In my view, through its history, through its actions, through its false words and deeds for decades, Iran has forgone the ability for us to shake on a deal that freezes their program."