Japan's Defense Ministry says fighter aircraft belonging to its Air Self-Defense Force and bombers from the US military have conducted joint drills over the East China Sea.

The ministry announced on Saturday that the tactical drills had been carried out that afternoon over waters northwest of the southern Japanese island of Kyushu.

The ministry released photos of the aircraft flying in formation.

Nine aircraft were involved in the drills. The Japanese Air Self-Defense Force contributed five F2 fighter jets. The US military provided two B1 bombers and two F16 fighter aircraft.

The US military's B1 bombers also took part in joint drills with the South Korean military on the same day.

North Korea has reacted sharply to the US-South Korean drills. The country has repeatedly conducted test launches of ballistic missiles in recent days. Observers believe that some of the launched projectiles were intercontinental ballistic missiles.

The ministry says the drills on Saturday showed that the Japanese Self-Defense Forces and the US military are ready to address the security situation in the region. It notes that the situation is becoming increasingly strained, due to the North's repeated missile test launches.

The ministry says an aim of the drills was to show that the two countries are close allies and that they are committed to addressing all possible contingencies.