The Japan Coast Guard has conducted two separate joint drills, one with the Maritime Self-Defense Force and the other with the US Coast Guard, in waters off the southwestern region of Kyushu.
The coast guard carried out the joint exercise with the MSDF on Wednesday with a focus on how to respond to suspicious vessels. The two parties confirmed radio communications and helicopters from both sides took off and landed on each other's vessels.
The Japan Coast Guard also conducted similar training with the US Coast Guard through Wednesday. The drill was based on a scenario that a suspicious vessel had been spotted in Japan's territorial waters. Officers confirmed procedures for jointly pursing the vessel and bringing it to a halt.
Japanese officials say the joint training with the MSDF was the third of its kind this year. They add that this is the first time such exercises have been carried out three times a year.
The officials also say the joint drill with its US counterpart that focused on suspicious vessels was the first of its kind.
They say the exercises were not intended to target any specific country.
But some sources have stressed the importance of strengthening coordination among the three parties in anticipation of China ramping up its activities in the waters surrounding Japan.