Iranian President Hassan Rouhani described the United States decision to exit the nuclear deal as a "big mistake" during a speech on Wednesday.
Rouhani says U.S. made a 'big mistake' leaving nuclear deal
He also threatened a "crushing response" if the U.S. goes ahead with plans to extend an embargo on Iranian trade of conventional arms, which the United Nations is set to lift later this year.
Under Iran's deal with world powers to accept limits to its nuclear programme in return for the lifting of sanctions, a U.N.
Weapons embargo is due to expire in October.
The U.S., which exited the deal in 2018, says it wants to extend the embargo.
Iran has gradually rolled back its commitments under the accord in response to the U.S. decision to quit, but says it wants the agreement to remain in place.