The accord took effect in January and envisions Iran curtailing its nuclear program in exchange for billions of dollars in sanctions relief.
But the head of Iran's central bank said in a speech Friday that Iran's counterparts "have not honored their obligations" and that "almost nothing" has been done.
Valiollah Seif complained that Iran still cannot access its frozen funds abroad and urged Washington to do more to encourage international banks to do business with Iran and allow Iran access to the US financial system. Otherwise, he says, the deal "breaks up on its own terms.