The U.S. has eased restrictions on the sale of mobile phones and other communications devices, software and services to Iranians, BBC News reported.

The move is intended to promote Iranians' political freedom, countering what the U.S. describes as Tehran's efforts to "silence its people".

The shift marks the first time Apple's iPhone can be exported legally to Iran.

The U.S. had toughened sanctions in recent years in an effort to force Iran to curb its nuclear programme.

The U.S. believes Iran is enriching uranium to levels that could be used in a nuclear weapon, but Iran insists its programme has peaceful objectives.

"The people of Iran should be able to communicate and access information without being subject to reprisals by their government," the U.S. treasury department said in a statement.