The People's Republic of China is holding a maneuver near the Taiwan Strait.
Beijing was responding to a high-ranking US diplomat's visit to Taiwan.
The combat exercises are a legitimate and necessary measure to respond to the current situation, said Ren Guoqiang, a spokesman for the Chinese Defense Ministry.
The visit of Keith Krach, a senior US State Department official, had previously sparked new tensions between Beijing and Washington.
China was firmly against any form of official exchange between the United States and Taiwan, a spokesman for the Beijing State Department warned when the US politician arrived.
A row was expected to meet Taiwan's President Tsai Ing-wen on Friday.
Talks about a trade agreement should also be on the agenda.
Beijing regards the island of Taiwan, south of mainland China, as a breakaway province that is to be reunited with the People's Republic - if necessary with military force.
While the Chinese leadership and Washington have drifted further and further apart in recent years, Taiwan's relations with the United States have improved significantly.
But according to Beijing's "One China Doctrine", no state that maintains diplomatic relations with the People's Republic is actually allowed to maintain official contacts with Taiwan.
This is the second visit by a high-ranking US politician to Taiwan within a few weeks, which Beijing sees as a gross provocation.
In August, US Secretary of Health Alex Azar traveled to Taiwan as the highest-ranking US representative in decades.
Even then, Beijing had warned Washington against "playing with fire".
Taiwan split from China in 1949.
Since independence advocate Tsai Ing-wen took office in 2016, tensions between Beijing and Taipei have intensified.
Beijing is now increasingly threatening "reunification" (read an analysis here).
Icon: The mirror
as / dpa