Military tensions with China are at their worst in more than 40 years, Taiwan’s defence minister said on Wednesday, promoting a new arms spending package to lawmakers days after record numbers of Chinese aircraft flew into the island’s air defence zone.

Tensions have hit a new high between Taipei and Beijing, which claims the democratic island as its own territory, and Chinese military aircraft have repeatedly flown through Taiwan’s air defence identification zone, though no shots have been fired and the planes have stayed away from mainland Taiwan.

Over a four-day period beginning last Friday, Taiwan reported close to 150 Chinese air force aircraft entered its air defence zone, part of a pattern of what Taipei calls Beijing’s continued harassment of the island. Just one incursion was reported on Tuesday. Asked by a lawmaker on the current military tensions with China at the parliament, defence minister Chiu Kuo-cheng said the situation was “the most serious” in more than 40 years since he joined the military, adding there was a risk of a “misfire” across the sensitive Taiwan Strait.

“For me as a military man, the urgency is right in front of me,” he told a parliamentary committee reviewing an extra military spending plan worth T$240bn ($8.6 billion) over the next five years for home-made weapons including missiles and warships.

China says Taiwan should be taken by force if necessary. Taiwan says it is an independent country and will defend its freedoms and democracy, blaming China for the tensions.

Chiu said China already has the ability to invade Taiwan and it will be capable of mounting a “full scale” invasion by 2025.

US President Joe Biden said on Tuesday he had spoken to Chinese President Xi Jinping about Taiwan and they agreed to abide by the Taiwan agreement.

Biden appeared to be referring to Washington’s long-standing “one-China policy” under which it officially recognises Beijing rather than Taipei, and the Taiwan Relations Act, which makes clear that the US decision to establish diplomatic ties with Beijing instead of Taiwan rests upon the expectation that the future of Taiwan will be determined by peaceful means.

Halt provocative actions towards Taiwan: Blinken

US secretary of state Antony Blinken called China’s recent actions around Taiwan “provocative and potentially destabilising”, urging leaders in Beijing to stop such behaviour.

“The actions we’ve seen by China are provocative and potentially destabilising,” Blinken said in an interview in Paris with Bloomberg Television. “What I hope is that these actions will cease because there’s always the possibility of miscalculation, of miscommunication, and that’s dangerous.

“It’s very important that no one take unilateral actions that change the status quo by force.”