Beijing claims Taiwan as part of its sovereign territory and has refused to rule out using military action to seize the island democracy.

The latest show of force follows a bumper round of arms sales to Taipei by the United States, Taiwan's main security backer.

Beijing warned on Monday that "external forces" arming Taipei would "push the Taiwan Strait into a perilous situation of imminent war", but did not mention any countries by name.

Foreign ministry spokesman Lin Jian said any attempts to stop China's unification with Taiwan were "doomed to fail".

AFP reporters in Pingtan -- a Chinese island that is the closest point to Taiwan's main island -- saw two fighter jets soaring across the sky and a Chinese military vessel in the distance.

Visitors to the tourist spot said they had been unaware of the drills as they milled around snapping photos.

A tourist surnamed Guo, from Inner Mongolia, told AFP she thinks a unification will "definitely happen".

"It's just a matter of time," she said.

- 'Live-fire training' -

China said early on Monday it was conducting "live-fire training on maritime targets to the north and southwest of Taiwan" in large-scale exercises involving destroyers, frigates, fighters, bombers and drones.

Military spokesman Shi Yi said Beijing would send army, navy, air force and rocket force troops for drills code-named "Justice Mission 2025".

He said the drills would focus on "sea-air combat readiness patrol, joint seizure of comprehensive superiority, blockade on key ports and areas, as well as all-dimensional deterrence outside the island chain".

Chinese authorities published a map of five large zones around Taiwan where the war games would take place.

Taiwan said China's designated exercise zones, some of which are within 12 nautical miles of its coast, have affected international shipping and aviation routes.

The island's government condemned China's "disregard for international norms and the use of military intimidation to threaten neighbouring countries", Presidential Office spokeswoman Karen Kuo said.

Its defence ministry said it had detected 89 Chinese military aircraft near its shores on Monday -- the highest number in a single day since October 2024. It also said it had detected 28 warships and coastguard vessels.

Taiwan's Civil Aviation Administration said China had declared a "Temporary Danger Area" for 10 hours on Tuesday, "which is expected to affect flight operations in the region".

Its military said it had established a response centre, deployed "appropriate forces" and "carried out a rapid response exercise", while its coastguard said it "immediately deployed large vessels".

The drills by China's ruling Communist Party "further confirm its nature as an aggressor, making it the greatest destroyer of peace", Taipei's defence ministry said.

- 'Stern warning' -

Chinese military spokesman Shi said the drills were "a stern warning against 'Taiwan Independence' separatist forces, and... a legitimate and necessary action to safeguard China's sovereignty and national unity".

Beijing's military released a poster about the drills showing "arrows of justice" -- one engulfed in flames -- raining down on a geographical outline of Taiwan.

And in an AI-generated video published by the force, eagles, sharks, wolves and bees transformed into Chinese military equipment, lashing Taiwan from the sea and air.

Another Pingtan sightseer, surnamed Lin, said she hoped to see mainland China and Taiwan unify eventually.

"I hope things can keep getting better and develop, and our relationships can become closer and closer," said the 22-year-old from the southwestern province of Sichuan.

State broadcaster CCTV reported that a core theme of the exercises was a "blockade" of key Taiwanese ports, including Keelung in the north and Kaohsiung in the south.

China's military last held large-scale drills involving live firing around Taiwan in April -- surprise manoeuvres condemned by Taipei.

China said this month it would take "resolute and forceful measures" to safeguard its territory after Taiwan said the United States had approved a major $11 billion arms sale.

Beijing announced fresh sanctions on 20 American defence companies last week, although they appeared to have little or no business in China.

Japan's Prime Minister Sanae Takaichi triggered a backlash from Beijing last month when she said the use of force against Taiwan could warrant a military response from Tokyo.