China has launched military exercises around Taiwan, saying the drills were a “stern warning” to “separatist forces” on the island state following a recent visit by Taiwan’s Vice President William Lai to the United States.

Lai, the front-runner to become Taiwan’s president at elections in January, returned from the United States on Friday, where he officially made only stopovers on his way to and from Paraguay.

The People’s Liberation Army’s Eastern Theatre Command, which has responsibility for the area around Taiwan, said on Saturday morning that it was carrying out joint naval and air combat readiness patrols around Taiwan.

It said it was also holding joint exercises and training of naval and air forces, focussing on subjects such as ship-aircraft coordination and seizing control, to test the forces’ “actual combat capabilities”.

“This is a serious warning against Taiwan independence separatist forces colluding with external forces to provoke,” it added.

Taiwan’s defence ministry strongly condemned the drills, saying it will dispatch appropriate forces to respond and has the ability, determination, and confidence to ensure national security. “The launch of the military exercise this time not only does not help peace and stability in the Taiwan Strait, but also highlights (China’s) militaristic mentality,” the ministry said.

China claims Taiwan as its own territory, and Beijing has not ruled out the use of force to take control of the democratic, self-governed island