Iran and the United States held in-depth negotiations in Oman over Tehran's rapidly advancing nuclear program on Saturday, ending the discussions with a promise for more talks and perhaps another high-level meeting next weekend.

The two sides are understood to have discussed the U.S. lifting of sanctions on Iran, with focuses on technical and key topics including uranium enrichment.

Leaders from the United States and Iran painted a positive but cautious picture of talks between the nations over Iran’s nuclear program Saturday, after the third phase of the discussions wrapped up in Oman.