The Japanese and U.S. defense chiefs agreed on Wednesday that their nations will undertake joint technological research to counter hypersonic weapons, as they work to closely align their national security strategies amid China's growing assertiveness in the Indo-Pacific region.

The talks between Defense Minister Yasukazu Hamada and his U.S. counterpart Lloyd Austin at the Pentagon — their first in-person meeting since Hamada's appointment last month — came amid heightened tensions over Taiwan following U.S. House of Representatives Speaker Nancy Pelosi's recent trip to the self-ruled island.

"China's coercive actions in the Taiwan Strait and in the waters surrounding Japan are provocative, destabilizing and unprecedented," Austin said at the outset of the meeting, apparently alluding to China's increased military activities in response to the high-profile U.S. visit to Taiwan in early August.