Usually a declaration from the Supreme Leader is enough.  “Iran’s president calls on Pope Francis to use influence to stop war in Middle East,” Al Arabiya, 11-20-24.

But haven’t they said from the first they would never build an atomic bomb, and that there was a fatwa prohibiting such?!  “Iran has offered to keep uranium below purity levels for a bomb, IAEA confirms,” Guardian, 11-20-24.

“What would Iran do: A race to the bomb or a deal with Trump?,” Iran International, 11-20-24.

“Ignoring threats, Western powers officially ask UN nuke watchdog to censure Iran,” Iran International, 11-20-24.