Beijing's defence ministry spokesman Wu Qian says Taiwanese President Lai Ching-tse "has seriously challenged the one-China principle... pushing our compatriots in Taiwan into a perilous situation of war and danger".
Democratic Taiwan is accustomed to frequent threats from China, which claims the island as part of its territory.
Beijing has said it will never renounce the use of force to bring Taiwan under its control, and has in recent years upped the rhetoric of "unification" being "inevitable".