"We urge the US to... stop emboldening and supporting Taiwan independence and avoid further damaging China-US relations and the peace and stability of the Taiwan Strait," Chinese foreign ministry spokesperson Guo Jiakun said.
Taiwan and China split in 1949 during the civil war that brought the communists to power on the mainland, with the defeated Nationalists fleeing across the Taiwan Strait to set up a rival government on the island.
China says the US has "gravely backpedalled" on its position on Taiwan after a government fact sheet was changed to remove a line on American opposition to independence for the breakaway province.
The latest row comes after the US State Department removed the phrase "we do not support Taiwan independence" from a fact sheet last week.
Tensions between the US and China over Taiwan's independence have spanned decades, particularly as Chinese warplanes have repeatedly flown close to the island's airspace.
