The Biden administration has been working to renew the 2015 nuclear deal, which placed curbs on Iran's nuclear program in exchange for billions of dollars in.
A Russian diplomat taking part in renewed talks with Iran said Tehran got much more than anyone expected as it negotiated with other nations to revive the 2015 nuclear deal.
The head of the UN nuclear watchdog, the International Atomic Energy Agency, will travel to Iran on Saturday as nuclear deal talks between Tehran and western states reach a critical crunch point.