President Hassan Rouhani, a relative pragmatist who pushed for the deal hoping to open Iranian’s reclusive society to the international economy, said Trump cannot change the agreement.

“Iran’s understanding of the nuclear deal was that the accord was not concluded with one country or government but was approved by a resolution of the U.N. Security Council, and there is no possibility that it can be changed by a single government,” he said on Iran state television Wednesday.

Foreign Minister Mohammad Javad Zarif, who negotiated the agreement on behalf of Iran, said the United States must stick to the agreed-upon details.

“Every U.S. president has to understand the realities of today’s world,” he said Wednesday, as reported by the Tehran Times. “The most important thing is that the future U.S. president sticks to agreements, to engagements undertaken.”