North Korea has slammed efforts to surveil its illicit trades with its exports to China reportedly on the rise.

Earlier this month, France and Canada dispatched military aircraft to a US Air Force base in Japan with the intention of monitoring Pyongyang's "illicit maritime activities" including ship-to-ship transfers involving North Korea-flagged ships evading United Nations sanctions.

On Tuesday, a North Korean foreign ministry researcher called the move an "imprudent" act, according to Seoul's Yonhap News Agency.