The talks seek to limit Iran's nuclear program in exchange for the lifting of some of the crushing economic sanctions the U.S. has imposed on the Islamic Republic.

Sultan Haitham bin Tariq Al Said is visiting Russia ahead of a third round of talks between Tehran and Washington.

Iran and the United States are preparing to start in-depth negotiations in Oman over Tehran’s rapidly advancing nuclear program, talks that likely will hinge on the Islamic Republic’s enrichment of ur