The United States and Iran held high-level talks in Oman on Sunday ahead of a looming deadline for a nuclear deal, but President Barack Obama warned that a "big gap" remained, Agence France Presse reports.
US Secretary of State John Kerry met Iran's Foreign Minister Mohammad Javad Zarif in the Gulf sultanate, with both sides facing political pressure at home over the long-running negotiations which have appeared close to deadlock for months.
Iran and world powers have set November 24 as the deadline to turn an interim agreement into a long-term settlement, but Obama warned it may not be possible.
"Are we going to be able to close this final gap so that (Iran) can re-enter the international community, sanctions can be slowly reduced and we have verifiable, lock-tight assurances that they can't develop a nuclear weapon?" Obama asked in an interview broadcast on CBS News on Sunday.
