China's Defence Ministry says there is no room for compromise over Taiwan and the US "should not have any illusions about this".
China says the issue of Taiwan, which it claims as Chinese territory, is the most sensitive in its ties with the US, the country that is also Taiwan's most important international backer and arms supplier.
Asked at a monthly news briefing in Beijing to comment on Sino-US military ties in the light of recent talks between the two presidents, Chinese Defence Ministry spokesman Wu Qian said having a healthy and stable relationship was good for both and what the world expected.
China is willing to maintain exchanges and co-operation with the United States, he added.
"However, for a period of time, the US side has said a lot of irresponsible things and done a lot of provocative things on Taiwan, the South China Sea, and close-up reconnaissance by warships and aircraft," Wu said.
China has principles for the development of relations between the two militaries, which is to say its sovereignty, dignity, and core interests cannot be violated, he added.
"Especially on the Taiwan issue, China has no room for compromise, and the US side should not have any illusions about this."
Democratically ruled Taiwan has denounced China for its stepped up diplomatic and military pressure to try to force the island into accepting Chinese sovereignty.
Taiwan President Tsai Ing-wen has vowed to defend the island, and says only its people can decide its future.
