WASHINGTON - US 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."
Obama said that 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 that we've 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 is still significant gaps between the international community and Iran and we have more work to do," Obama 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."
Obama was speaking after he met with Secretary of State John Kerry, who reported progress after he joined the talks in Vienna to speak with Iranian Foreign Minister Mohammad Javad Zarif.
Zarif, a member of President Hassan Rouhani's reform-minded administration, is looking for a historic agreement with the United States to relieve Western sanctions that have severely impacted the Islamic republic's economy.
Iran insists it is not seeking the atomic bomb but has stayed firm on its right to peaceful use of nuclear energy in the talks with six powers -- Britain, China, France, Germany, Russia and the United States.
Under an interim agreement reached in November, Iran froze its uranium enrichment in return for about $7 billion in sanctions relief.
Israeli Prime Minister Benjamin Netanyahu has accused Iran of bad intentions and criticized the deal. US lawmakers, who are widely supportive of Israel, have demanded rigorous checks on any agreement with Iran.
Rouhani's government in turn faces pressure from hardliners in the clerical regime who see the United States as an enemy.
Tehran and Washington have pursued exhaustive talks on the nuclear deal -- itself a dramatic turnaround in relations as the two countries had virtually no official communication since the aftermath of the 1979 Islamic revolution, which toppled the Western-oriented shah.