The United States and Iran started a second day of talks aimed at breaking the deadlock on a nuclear deal Monday, with the clock ticking down to a November 24 deadline.
US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif are meeting in Muscat, capital of the Gulf sultanate of Oman.
At stake is a long-term nuclear agreement between Iran and the P5+1 powers -- Britain, China, France, Russia and the United States plus Germany.
Kerry and Zarif held more than five hours of talks on Sunday, with former EU foreign policy chief Catherine Ashton, the lead negotiator in the talks.
They resumed their negotiations just before 11:30 am (0730 GMT), a US official said, but the meeting was closed to the press.
With both Iran and the US facing pressure at home over the talks, President Barack Obama said in a CBS News interview screened Sunday that the sides were still far apart.