Nuclear negotiations between Iran and six major world powers are likely to continue for at least another day, the United States and Iran indicated late on July 13.
Talks in Vienna have made real progress but “significant issues” remain, the White House said, while adding that Iran faced some tough decisions.
"They have made genuine progress...but there continues to be some sticking points that remain unresolved," White House spokesman Josh Earnest told reporters on July 13 in Washington.
Earnest said that if the talks are not completed by the end of the day on July 13, then parties will agree to a short-term extension of the interim agreement.
He added that the U.S. negotiating team will remain in Vienna as long as the talks remain “useful.”
Iran's President Hassan Rohani is expected to address the nation on state television when the nuclear talks have concluded, IRNA reported, quoting an official at the presidential office.
Iranian media quoted Rohani as saying on July 12 that the sides were "very close" to a deal.
"We are so close that if you look down from below you feel as if we have got there, but when you do get there you know there are still some steps to take," said Rohani.
All sides have said they are close to reaching a deal. But U.S. Secretary of State John Kerry said after meeting with his Iranian counterpart, Mohammad Javad Zarif on July 12, that “major issues” still must be resolved.
Western official have said that Iranian and U.S. negotiators would need time to consult their capitals once an agreement was reached.
Meanwhile, in Washington, the Republican Senate Majority Leader Mitch McConnell and other congressional leaders were expressing doubts about a historic agreement with Iran -- predicting that President Barack Obama could face hurdles in Congress.
McConnell said: “This is going to be a very hard sell for the administration.”
Because the deadline for a deal has been extended three times during the Vienna talks, Congress now has 60 days to assess the deal and Obama is obliged to wait for that review before easing sanctions.
During those two months, Republican lawmakers could try to build a veto-proof majority behind new legislation that could impose new sanctions on Iran or prevent Obama from lifting the existing sanctions.
Such a development could effectively derail any final deal that might be reached in Vienna.
Global powers and Iran are seeking a deal that would limit Tehran's nuclear activities, making it harder for Iran to develop nuclear weapons, in exchange for relief from UN, U.S., and EU sanctions that have harmed its economy.
Under a framework agreement reached in April in Lausanne, Switzerland, Iran is required to cut the number of its centrifuges from more than 19,000 to just over 6,000.
It also is required to cut back its stockpile of enriched uranium -- which can be used to make a nuclear bomb if enriched to a high enough level -- from more than seven tons to about 350 kilograms.
The aim is to ensure that it would take Iran at least a year to acquire enough fissile material to build a nuclear bomb.
With additional reporting by Hannah Kaviani of RFE/RL's Radio Farda in Vienna, Reuters, AP, AFP, ISNA, Interfax, TASS, and BBC