US Secretary of Defense Lloyd Austin and new Japanese Defense Minister Yasukazu Hamada on Monday affirmed their commitment to strengthening the bilateral alliance and condemned China's firing of ballistic missiles that fell in waters near Japan during recent military exercises around Taiwan, the two governments said.

The United States and Japan also announced the same day that the two security allies and South Korea had recently engaged in a ballistic missile tracking exercise off the coast of Hawaii, underscoring their trilateral cooperation to respond to the North Korean nuclear threat.

The phone call between the two defense chiefs took place after Hamada replaced Nobuo Kishi, who had held Japan's defense portfolio for about two years, in a Cabinet reshuffle last week. Hamada was previously defense minister between 2008 and 2009.

It also came amid growing tension in the region following US House of Representatives Speaker Nancy Pelosi's visit to Taiwan, which has infuriated Beijing as it views the self-ruled island as its own.

According to the Japanese Defense Ministry, Hamada and Austin "strongly criticized" China's firing of ballistic missiles during the large-scale drills near Taiwan. Some of the missiles fell in Japan's exclusive economic zone.

The two agreed to seek close and "unassailable" coordination, including at the ministerial level, so that the two countries can "deal with any kind of situation in the region," the ministry said.

Austin congratulated Hamada on his appointment and the two confirmed "cooperation on an array of concrete and innovative defense initiatives aimed at ensuring a free and open Indo-Pacific," the Pentagon said.

Japan is seeking to bolster the capabilities of its defense forces through increased spending in a rapidly changing security environment. A review of national security strategy and key defense policy documents is planned this year.

The North Korean nuclear and missile threats continue to pose a challenge, raising the need for closer cooperation among Japan, the United States and South Korea even as relations between Tokyo and Seoul remain frosty largely due to wartime compensation issues.

Based on an agreement reached by the defense chiefs of the three countries in June, the Japanese Maritime Self-Defense Force, the US Navy and South Korean navy participated in a missile warning and ballistic missile search and tracking exercise during a weeklong multinational drill from Aug. 8, according to the Pentagon.

Trilateral drills to deal with the North Korean ballistic missile threat had not been held for years amid the frayed ties between Japan and South Korea.

Earlier Monday, Austin said he tested positive for the novel coronavirus for the second time this year. He said his symptoms were mild and he would maintain his normal work schedule virtually.