TAIPEI - Taiwan on Tuesday urged Beijing to exercise restraint after a Chinese military aircraft entered its air defense zone following a recent spate of drills that have ratcheted up cross-strait tensions.

The Chinese military plane was spotted in Taiwan's air defense zone on Sunday, according to the defense ministry.

Chinese military aircraft have flown near Taiwan's air defense identification zone (ADIZ) on seven other occasions since July.

"We keep on high alert to prevent unidentified or Chinese planes and ships from entering our air and sea space. We urge restraint to maintain peace in the Taiwan Strait," said ministry spokesman Chen Chung-chi.

Taiwan has scrambled aircraft to monitor the Chinese planes each time they have flown near the island.

Relations with China have rapidly deteriorated since the inauguration of President Tsai Ing-wen who refuses to acknowledge both sides are part of "one China".

Beijing considers Taiwan part of its territory and has said it would respond with force if it ever announced a formal breakaway.

Beijing has cut all official communication with Taipei and stepped up pressure on Tsai's government, including staging a string of naval and air drills near Taiwan since last year.

Beijing sent its only aircraft carrier, the Liaoning, through the Taiwan Strait in January during a drill and also in July when it was en route to Hong Kong.

The Mainland Affairs Council, Taiwan's top China policy-making body, also urged restraint on Tuesday and protested Beijing's moves that heighten regional tensions.

"China's provocation and intimidation is unhelpful for long-term development in cross-strait relations," said spokesman Chiu Chui-cheng.

In 2014, two Chinese Y-8 aircraft also entered Taiwan's air defense zone en route to a disputed area in the South China Sea under Tsai's Beijing-friendly predecessor Ma Ying-jeou.