China's growing military is increasingly flexing its muscles and held live-fire drills last week in the Taiwan Strait -- the narrow waterway separating the Chinese mainland from Taiwan -- following weeks of naval manoeuvres in the area.

Chinese officials said their drills were to safeguard Beijing's territorial sovereignty, a major priority for President Xi Jinping.

Although Taiwan is a self-ruling democracy, it has never formally declared independence from the mainland and Beijing still sees it as a renegade province to be brought back into the fold, by force if necessary.

Cross-strait relations have steadily deteriorated since 2016 when President Tsai Ing-wen took office, largely because she refuses to accept that Taiwan is part of "one China", and because Beijing is deeply suspicious of her traditionally pro-independence Democratic Progressive Party.

Taiwan's five-day drill, codenamed "Han Kuang", which means "Han Glory", will start from June 4.

"Simply put, the main goal of the drill is to make any Chinese communist military mission to invade Taiwan fail," defence ministry spokesman Chen Chung-chi told reporters.

"It simulates this year's situation and we are taking into consideration China's air and naval movements in the region," he added.

This year's drill will enlist the coastguard and National Airborne Service Corps, which handles rescue flights, for the first time for "comprehensive defence", Chen said.

Civilian drones will also participate in the drill for the first time to conduct surveillance and mark targets, while civilian telecom service providers will assist in maintaining communication and control, the ministry said.

"It's not just soldiers' duties to protect the country. Everyone has the responsibility since our defence budget is limited," Chen said.

Taipei dismissed China's military exercises in the Taiwan Strait last week as "routine" after expected large-scale naval manoeuvres failed to materialise and called it the "cheapest way of verbal intimidation and sabre-rattling".

Chinese state media reported Tuesday that a flotilla of Chinese naval vessels held a "live combat drill" in the East China Sea, the latest show of force in disputed waters that have riled neighbours.

Earlier this month Chinese president Xi inspected the convoy as it conducted exercises in the disputed South China Sea.

The flotilla then held two separate drills last week in waters on either side of Taiwan, infuriating the government in Taipei.