The United States supports Japan's protests over Chinese ships venturing into the economic waters near disputed East China Sea islands, the commander of the U.S. Forces in Japan said Wednesday.

“The United States is 100% absolutely steadfast in its commitment to help the government of Japan with the situation in Senkaku,” Lt. Gen. Kevin Schneider said of the group of islands, which are controlled by Japan.

China also claims the islands, which it calls Diaoyu.

“That’s 365 days a year, 24 hours a day, seven days a week. There is no deviation in that regard,” Schneider told reporters.

Japan has long protested the repeated presence of Chinese coast guard vessels in the waters. Schneider also noted such incursions had increased recently.

He called China the “No. 1 challenge” in regional security, although North Korea was the more “immediate threat,” given its weapons development.

Schneider said the U.S. was offering Japan surveillance information and other support, such as “reconnaissance capability,” which refers to monitoring the whereabouts of a potential enemy, to help Japan “assess the situation and to figure out exactly what’s going on in the water in and around the Senkaku.”

China shrugged off such concerns.

Wang Wenbin, spokesperson for the Chinese foreign ministry, reasserted China’s claim to the islands, stressing it was the country’s “inherent right to carry out patrol and law enforcement” activities in the area.

“We hope that relevant parties will do something helpful to maintain regional peace and stability and avoid words and deeds that are not conducive to regional peace and stability,” Wang told reporters at a daily press briefing.

Schneider was speaking at an online press briefing that mostly touched on U.S. efforts to combat the coronavirus among its forces in Japan.