Washington says Secretary of State John Kerry will meet during the weekend with Iranian Foreign Minister Mohammad Javad Zarif in Geneva, where U.S. and Iranian negotiators are to resume talks on February 20.
The talks between Kerry and Zarif have been scheduled for February 22, ahead of a deadline next month on a framework nuclear agreement between Iran and six world powers.
The meeting follows a report by the International Atomic Energy Agency (IAEA) on February 19 that says Iran has not addressed all suspicions it may have researched an atomic bomb -- potentially complicating efforts to reach a final nuclear deal by the end of June.
The IAEA report says Tehran had still not provided information about two areas of the IAEA's investigation that was due in August 2014.
The U.S. negotiating team in Geneva on February 20 is led by Under Secretary of State Wendy Sherman.