TEHRAN — Iran sought Tuesday to spell out in its clearest terms yet that it is not seeking nuclear weapons, highlighting a religious decree issued by Supreme Leader Ayatollah Ali Khamenei that bans nuclear weapons.

The latest reference to Khamenei’s declaration is seen as a bid to close the door on debates that Iran may have carried out atomic bomb trigger tests as inspectors from the UN atomic watchdog were on their way to Tehran for a new round of discussions.