The one-day exercise will enhance interoperability and tactical and technical coordination between the three countries. 

The exercises brought together the USS Ronald Reagan aircraft carrier, the guided missile cruiser USS Chancellorsville, the Aegis-equipped destroyer USS Barry, South Korea's destroyer Munmu the Great, Japan's tanker Asahi, among others.

The drill took place off the east coast of the Korean peninsula, one day after North Korea conducted its third missile launch in a week.