Chinese navy soldiers guard Great Wall - 218 of Navy Submarine at Qingdao Port on April 22, 2009 in Qingdao of Shandong Province, China. Guang Niu/Getty BEIJING (Reuters) - China's Foreign Ministry urged the United States on Thursday to act and speak cautiously after the U.S. defense chief repeated Washington's opposition to any "coercive unilateral" actions by China over a group of islets disputed with Japan.

Visiting Tokyo, US Secretary of Defense Ash Carter expressed opposition to any moves by China to undermine Japan's administrative control of uninhabited islands in the East China Sea, known as the Senkaku in Japan and the Diaoyu in China.

Chinese Foreign Ministry spokeswoman Hua Chunying said that no matter what anyone said or did, it would not change the facts of China's sovereignty or its determination to defend its territory.

"We urge the US sides to speak and act with caution, to strictly abide by their promises not to take a position on the relevant territorial ownership issue, and do more to benefit regional peace and stability and not the opposite," she said.

Carter also welcomed progress toward the first update in US-Japan defense cooperation guidelines since 1997.

The revision will expand the scope for interaction between the allies in line with Prime Minister Shinzo Abe's push to ease the constraints of Japan's pacifist constitution on the nation's military.

(Writing by Ben Blanchard; Editing by Jeremy Laurence)