A delegation of North Korean experts in nuclear warheads and ballistic missiles visited a military site near Tehran in April amid talks between world powers and Iran over its nuclear program.
"The delegates included nuclear experts and experts in various elements of ballistic missiles including guidance systems," Reuters reports with reference to NCRI.
According to the agency, there have previously been unconfirmed reports of ties between Iran and North Korea on ballistic missile cooperation, although nothing specific in the nuclear field.
