“I do not see Trump as worthy of any message exchange, and I do not have any reply for him, now or in future,” Iranian state media quoted Khamenei as telling the Japanese premier.

U.S. allies in Europe and Asia have repeatedly expressed concern that tension between the United States and Iran could escalate into an armed conflict. Abe warned on Wednesday of unintended clashes in the Middle East, after meeting Iranian President Hassan Rouhani.

A year after the United States abandoned an agreement between Iran and world powers to curb Tehran’s nuclear programme in return for lifting sanctions, confrontation between the two foes has reached a new pitch.