New US Defense Secretary Lloyd Austin on Sunday, during his first phone call with his Japanese counterpart, reaffirmed America's commitment to defending the disputed East China Sea islets known as the Senkaku in Japan, Jiji news agency reported.
Austin and Japanese Defense Minister Nobuo Kishi confirmed that Article 5 of the US-Japan security treaty, which stipulates US defense obligations to Japan, covers the Senkaku Islands, Jiji said. The islets are known as the Diaoyu in China.
The defense ministers also reaffirmed their opposition to any unilateral act that would undermine Japan's right to administer the islands, Jiji said.
Japan has become increasingly concerned about Chinese activity in the East China Sea, including incursions into waters around the disputed islands.
The talks marked the first ministerial talks between Tokyo and Washington since US President Joe Biden took office on Wednesday. Retired Army general Austin made history on Friday by becoming America's first Black defense secretary.
Japan's defense ministry was not immediately available for comment.
US Indo-Pacific Command said on Sunday a US Navy strike group entered the South China Sea on Saturday, the same day Taiwan reported a large incursion of Chinese bombers and fighter jets into its air defense identification zone near the Pratas Islands.