White House national security adviser Jake Sullivan said on Wednesday the United States and its allies have made progress in Iran's nuclear talks but issues remain, and it is unclear if they will be resolved.
"We've made progress over the course of the last several weeks. There are still some issues left," Sulllivan told reporters aboard Air Force One as President Joe Biden flew to Brussels.
He said it is "unclear if this will come to closure or not" but the allies are trying to use diplomacy to put Iran's nuclear program "back in a box."
US State Department spokesperson Ned Price said on Tuesday that the onus is now on Iran on whether it is willing to enter into a mutual return to compliance with the 2015 nuclear deal with world powers.
A return to the deal remained uncertain and was not imminent, Price said, despite optimism in recent weeks that indirect talks between Iran and the United States could soon produce an agreement.
