The defence ministry said it scrambled aircraft to broadcast warnings after 36 fighter jets, 12 H-6 nuclear-capable bombers and other planes entered its southwest air defence identification zone (ADIZ).

The ADIZ is not the same as Taiwan's territorial airspace but includes a far greater area that overlaps with part of China's own air defence identification zone and even includes some of mainland China.

Self-ruled democratic Taiwan lives under the constant threat of invasion by China, which views the island as its territory and has vowed to one day seize it, by force if necessary.

In the last two years Beijing has begun sending large sorties into Taiwan's defence zone to signal dissatisfaction at key moments -- and to keep Taipei's ageing fighter fleet regularly stressed.

China marked its National Day on Friday with its then biggest aerial show of force, buzzing the island with 38 warplanes.

That was followed by another incursion by 39 planes on Saturday, sparking criticism from Washington.

"The United States is very concerned by the People's Republic of China's provocative military activity near Taiwan, which is destabilising, risks miscalculations, and undermines regional peace and stability," US State Department spokesman Ned Price said in a statement on Sunday.

"We urge Beijing to cease its military, diplomatic, and economic pressure and coercion against Taiwan."

Beijing has ramped up pressure on the government of President Tsai Ing-wen since she came to power in 2016, as she rejects its stance that Taiwan is part of "one China".

Last year a record 380 Chinese military jets made incursions into Taiwan's defence zone, and the number this year as of early October has already exceeded 600.