The military dispatched reconnaissance aircrafts to surveil simulated incoming ships, followed by tanks firing rounds as the mimicked enemy landed at the Port of Hualien in eastern Taiwan.

Attack helicopters released flares and F-16 fighter jets also launched assaults, backing up on-the-ground battle against the "enemy" troops -- who wore red helmets to differentiate themselves.

While the ministry did not specify the annual drill simulated a Chinese invasion, it said that the drill is to "show determination to safeguard peace in the Taiwan Strait and national security."

The Taiwan Strait is the waterway that separates the island from China.

It comes after Tsai last month warned against what she called Beijing's "military expansion" -- the increase of Chinese air and naval drills around the island since she came to power in May 2016 -- and amid a new row over flight routes in the strait.

Beijing sees the self-ruling island as part of its territory, to be reunified at some point, and by force, if necessary.

Cross-strait relations have turned frosty since the inauguration of Tsai, who refuses to acknowledge self-ruling, democratic Taiwan is part of "one China."

The drill on Tuesday takes place annually prior to Lunar New Year holiday -- which lands in mid-February this year -- as a way to boost public confidence in Taiwan's defence capabilities.

"Our combat readiness has no holidays," Huang Kai-sen, a lieutenant general, told AFP.

"In order for our citizens to feel safe during the Chinese New Year, we are standing by and on guard 24 hours a day," he said.

Tensions have been growing this month since China started new flight routes in the strait without consulting Taiwan.

Taipei slammed the move as reckless and said it could threatened the island's security.

It has retaliated by blocking nearly 200 flights between Taiwan and China by Chinese airlines during the Lunar New Year period.

China also sent its sole operational aircraft carrier the Liaoning through the Taiwan strait twice this month.

While China's defence ministry urged Taiwanese not to worry as there was nothing unusual, the act is still viewed as a show of strength by Beijing.