Days after the island’s vice president visited the US, the Chinese military began conducting drills surrounding Taiwan as a “stern warning” against what it dubbed cooperation between “separatists and foreign forces,” according to the defense ministry.

In order to strengthen ties with his government’s final South American diplomatic partner, Paraguay, Taiwanese Vice President William Lai recently traveled there, stopping in San Francisco and New York City along the way. The ruling Communist Party on the mainland asserts that democratic Taiwan is a part of its territory and that it has no right to manage international ties.

A spokesperson for China’s Eastern Theater Command said in a brief statement that the military exercises involved the coordination of vessels and planes and their ability to seize control of air and sea spaces.

It was also testing the forces’ “actual combat capabilities,” Shi Yi said. The drills were a warning over provocations from pro-Taiwan independence forces and foreign forces, he added.

The command released footage of the drills online that showed soldiers running, as well as military boats and planes.

State media CCTV reported that missile-equipped boats and fighter jets were involved in the operation and that units worked together to simulate the surrounding of Taiwan.

Taiwan’s defense ministry strongly condemned what it called “irrational, provocative moves” in a statement. It said it would deploy appropriate forces to respond to the drills and take action to “safeguard freedom and democracy.”

It said its military would stand ready in the face of the threats posted by the Chinese army, adding that its forces have “the ability, determination and confidence to safeguard national security.”

It posted a video on Facebook that showed previous military drills and said the Chinese military exercises reflected a militaristic mentality.

The Taiwanese government’s China-policy making Mainland Affairs Council also said that Taiwan’s people are determined to defend themselves and will never succumb to threats of force.

China should stop using force and intimidation and start dialogue, it said in a statement.

As for Taiwan’s ruling Democratic Progressive Party, it stated that as well as trying to put pressure on the island, China’s military drills are also intended to influence Taiwan’s elections, which take place in January.