Taiwan's president watched naval drills simulating an attack on the island Friday, days before Beijing is set to hold live-fire exercises nearby in a show of force.
Relations between self-ruling Taiwan and China have deteriorated since Tsai Ing-wen came to power almost two years ago, largely because she refuses to accept the "One China" formula governing relations.
Beijing regards the island as a rogue territory - to be reunited by force if necessary - even though the two sides split in 1949 after the Chinese Civil War.
China's growing military is increasingly flexing its muscles and will hold live-fire drills next week in the Taiwan Strait - the narrow waterway separating the Chinese mainland from Taiwan - following weeks of naval maneuvers in the area.
Tsai boarded the Kee Lung destroyer to supervise as troops practiced defending against an attack on the northeastern port of Suao.
It was the first time she has supervised a drill from onboard a warship.
"I believe our countrymen will have great faith in the military's combat capabilities and its determination to defend our country after today's drill," Tsai said on the destroyer's deck after it returned to port as the exercise ended.
Tsai said "we are very confident of our military" when asked to comment on Beijing's planned live-fire drill in the Taiwan Strait next week.
"It's a routine drill that our military will fully monitor and has made relevant preparations," she said.
Taiwan's ministry of defense said the exercise was staged in light of a "changing international and regional security situation" to test the military's combat readiness and its ability to defend Taiwanese territory.
In fact, reports are saying that the islands of Vanuatu in the South Pacific Ocean have recently been designated as possible sites for Chinese naval-military buildup, a move which would de-facto affect regional balance of power which has been in place since the end of the Second World War, which would be an "incredibly aggressive signal towards the United States and Australia" according to Pacific Affairs expert at the Australian National University, Graeme Smith.
Some 20 warships and four F16 fighter jets took part in Taiwan's drill, one of the largest naval maneuvers since Tsai took office in May 2016.
Tsai has warned against what she called Beijing's "military expansion" - the increase in Chinese air and naval drills around the island since she took office in May 2016.
Chinese warplanes conducted 25 drills around Taiwan between August 2016 and mid-December last year, according to Taipei.
On Thursday, Chinese President Xi Jinping made a surprise visit to naval forces in the disputed South China Sea, where he stressed the "urgent" need to build a powerful navy.
China's sole aircraft carrier, the Liaoning, sailed through the Taiwan Strait on March 20, the same day that Xi issued a public warning against attempts to "separate" from China.
Xi's naval visit came after a US aircraft carrier sailing though the South China Sea gave a demonstration Tuesday for members of the Philippine government.
Washington recently agreed to allow US defense contractors help Taiwan construct its own submarines, sparking a warning from Beijing to Taipei against "playing with fire to burn itself".