The Panama Canal Authority has fined a North Korean cargo ship US$1 million after it was caught with an undeclared shipment of Cuban weapons in July.
The canal administrator, Jorge Quijano, said the ship was sanctioned because "it put our canal and our people at risk to a certain point".
The fine was levied on the freighter's captain and owners, he said, adding that the vessel was barred from unmooring until they paid at least two-thirds of the penalty.
He said the penalty could change depending on the response of the ship's owners, but they had not replied.
The Panamanian government said last month that a United Nations report found that the shipment was in violation of UN sanctions against arms transfers to North Korea's regime.
The ship, the Chong Chon Gang, was intercepted on July 10, as it tried to enter the Panama Canal, on suspicion it was carrying drugs.
Authorities instead uncovered 25 containers of military hardware, including two Soviet era MiG-21 fighter jets, air defence systems, missiles and command and control vehicles.
Both Havana and Pyongyang said they were "obsolete" Cuban arms being shipped to North Korea for refurbishment under a legitimate contract.
The ship's 35 crew are being detained at a former US military base on arms trafficking charges. They face up to 12 years in prison.