China's statement comes after US had blamed Chinese military involvement in recent cyberattacks against Google.
Defence Ministry spokesperson Huang Xueping, "The Chinese side urges the US side to speak and act cautiously to avoid further damage to bilateral relations and peaceful cross-strait development."
Sino-US ties have also been strained since Google said last month it was considering shutting down its Chinese-language search engine over hack attacks and government web censorship.
Google has said it believes those attacks originated in China, and recent reports said they had been traced back to two schools in China, one of which is linked to the military.
Huang called the accusations of links between Internet hackers and the Chinese military "baseless and irresponsible and had been hyped up for ulterior motives."