"I appreciate greatly the dedication and professionalism shown by all who participated in the search efforts", Williams said.
The Chinese Ministry of Defence said on Thursday that its warship Liuzhou, from the South China Sea Fleet, was working with the United States to find the missing marine "in the spirit of humanitarianism".
A member of Chinese Navy stands watch as the guided missile destroyer USS Stethem arrives at the Shanghai International Passenger Quay for a scheduled port visit in Shanghai, China.
The Chinese navy and two Japanese military ships aided in the search.
The destroyer was conducting routine operations in global waters west of the Subic Bay in the Philippines, according to ABC News America.
China has strongly objected to repeated freedom of navigation missions by the U.S. Navy in the South China Sea, where Beijing has rattled neighbors by constructing seven made-man islands in the disputed waters and fortifying them with radars and missiles.
The Stetham is homeported in Yokosuka, Japan. An investigation is underway. The US, Japan and China "spent 79 hours in a comprehensive search that covered roughly 25,900 square kilometres", the US 7th Fleet said.
Japanese and U.S. naval forces have been holding drills in the contested South China Sea in the face of Beijing's increasing assertiveness over its maritime claims in the region.
In July, the Chinese Foreign Ministry voiced protest over U.S. destroyer Stethem sailing close to disputed islands in the South China Sea.
The move drew a sharp rebuke from the Chinese, who called the operation "provocative" and said such actions "violate China's sovereignty and threaten China's security".