The Panamanian government said the Cuban weapons found under sacks of sugar, including equipment for launching missiles, "without a doubt" violated sanctions meant to halt sophisticated arms sales to North Korea.
A UN panel of experts monitoring sanctions against North Korea visited Panama in mid-August to investigate the arms seizure.
After the seizure, Cuba said the cargo included "obsolete defensive weapons" including two MiG-21 jet aircraft and two anti-aircraft systems that were being shipped to North Korea "to be repaired and returned".
North Korea said it had a legitimate contract to overhaul ageing weapons to be sent back to Cuba.
Years of sanctions have restricted if not stopped North Korea's sale of arms in the Middle East, Asia and Africa. It is also hurting its ability to procure conventional military equipment,