Taiwanese officials on Thursday simulated countering a Chinese maritime blockade with a tabletop exercise, using a scenario in which China demands any shipping to the island first gets Beijing's approval and also boards or even seizes ships.
China has never renounced the use of force to bring Taiwan under its control and regularly sends its military around the island.
But Taiwan's government has become more wary of other forms of non-military pressure that Beijing could exert to try to control Taipei, like using its coast guard to try to enforce legal jurisdiction over shipping to the island.
This month, China's Coast Guard mounted what it said was a "law enforcement" patrol off Taiwan's east coast, saying it inspected shipping. Taiwan denounced the move, while the US, France, Britain and Germany also expressed concern.
Speaking to a regular meeting of Taiwan President Lai Ching-te's Whole-of-Society Defence Resilience Committee, National Security Council Deputy Secretary-General Lii Wen said the tabletop drill was carried out earlier on Thursday.
In the scenario, China's coast guard announces that China would require ships entering and leaving Taiwanese ports to complete declarations through the China International Trade Single Window, a government portal for trade procedures, Lii said.
China would then gradually adopt measures like inspections, boardings, searches, and seizures of vessels, progressively increasing "interference with Taiwan's maritime resupply," he added.
In the drill, Taiwan's response is multifaceted, with its own Coast Guard carrying out "strong front-line law enforcement and response actions," while the military conducts immediate combat readiness drills, Lii said.
Bodies including the defence and foreign ministries would embark upon a publicity campaign, saying China's actions like illegal boarding and inspection violate international law and infringe upon freedom of navigation, he added.
China's Taiwan Affairs Office did not immediately respond to a request for comment. China recognises no claims of sovereignty by Taiwan.
"Our law-enforcement patrols in the relevant waters are legitimate and necessary and are a just action to safeguard national territorial sovereignty and maritime rights and interests," Chinese defence ministry spokesperson Zhang Xiaogang said in Beijing earlier on Thursday.
Speaking on Thursday at the opening of the resilience committee meeting, Lai said China's "acts of expansion carried out under the guise of law enforcement" undermine the security, peace and stability of the region.
"Taiwan's efforts to strengthen its self-defence capabilities, maintain the peaceful and stable status quo, and safeguard its democratic and free way of life are absolutely not provocations," he added.
(Reporting by Ben Blanchard; Additional reporting by Antoni Slodkowski in Beijing; Editing by Thomas Derpinghaus)