China sharply escalated tensions in the taiwan strait on friday, approaching taiwan with multiple jets at three different locations just as the countrys president was about to receive a senior us government official.

The incursions raise further concern that taiwan has become a flashpoint for intensifying us-china rivalry.

Taiwans ministry of defence said the peoples liberation army air force crossed the taiwan strait median line and entered the countrys air defence buffer zone with two h-6 bombers and 16 fighters. taiwans air force scrambled fighters and deployed [its] air defence missile system to monitor the activities, the ministry said.

China claims taiwan as part of its territory and threatens to attack it if taipei refuses to submit to its control indefinitely.

The taiwan strait median line is an unofficial dividing line that beijing and taipei largely respected for decades until the pla air force began occasionally crossing it last year.

Since then, the chinese military has steadily increased military pressure on taiwan and recently held another large-scale exercise inside taiwans air defence buffer zone.

Fridays exercise was launched as keith krach, us undersecretary of state, was due to meet president tsai ing-wen. he is the most senior state department official to visit taiwan since the us switched diplomatic recognition from taipei to beijing in 1979.

On friday morning, chinas defence ministry announced combat drills in the taiwan strait, an action it said was deemed necessary to safeguard national sovereignty.

Recently the us and the democratic progressive party have stepped up collaboration and frequently stirred up trouble, said a defence ministry spokesperson. those who play with fire will get burned.

Both the timing of the manoeuvre ahead of the meeting between ms tsai and mr krach and beijings language mirrored chinas move when alex azar, us health secretary, became the most senior us cabinet official to visit taiwan in more than 40 years last month. but fridays manoeuvres were far larger than those during mr azars visit.

According to a map released by taiwans defence ministry, two bombers and several fighters flew into the south-western corner of taiwans air defence buffer zone, an area where the pla has been operating almost incessantly in recent weeks.

In addition, eight pla fighters crossed on to the taiwan side of the median line near taoyuan and hsinchu, a densely populated and heavily industrialised area south-west of taipei where most of the countrys high-tech industry is concentrated.

The incursions took place in an area earmarked for regular patrols by taiwans air force, making them a high-risk manoeuvre, an air force officer said. another four chinese fighters crossed the median line north-west of the capital.

Liberty times, taiwans largest-circulation daily newspaper, reported from hualien, an east coast city with a large air base, that taiwanese fighters scrambled in response to the chinese incursions were armed with short and medium-range air-to-air missiles. the paper published a photo showing soldiers unloading air-to-air missiles next to a fighter parked in an aircraft shelter.

A spokesperson for taiwans presidential office said chinas behaviour was not conducive to improving their international image.