Taiwan demanded Wednesday that China end its ongoing military activity in nearby waters, which it said is unilaterally undermining peace and stability in the Taiwan Strait and disrupting international shipping and trade.

The Foreign Ministry, in a statement posted on its website, said it was responding in part to the activities of a “large number” of Chinese naval and coast guard ships in the first-island chain, the Pacific archipelago off the Asian continental mainland that includes Japan, Taiwan and part of the Philippines.

“The Ministry of Foreign Affairs solemnly demands that the Beijing authorities immediately stop military intimidation and all irrational activities that endanger regional peace and stability,” the statement said.

Taiwan defence officials say they have detected Chinese ships since Monday, both off Taiwan and farther out along the first-island chain. They described the formations as two walls designed to demonstrate that the waters belong to China.

China restricted airspace off its southeast coast from Monday to Wednesday, an indication that it was planning to hold drills, but the country's People's Liberation Army has not confirmed whether it is doing so.

Taiwan has been expecting drills following stops by its president, Lai Ching-te, in Hawaii and the US territory of Guam during an overseas trip last week. China claims self-governing Taiwan as its territory and opposes any official contact with America and other foreign governments.

A Chinese spokesperson didn't comment directly on any military exercises but said in a statement posted online Wednesday that the government would not let provocations by Taiwan in collusion with external forces go unchecked.

"We will take necessary measures to resolutely defend national sovereignty and territorial integrity, maintain peace and stability in the Taiwan Strait and safeguard the fundamental interests of compatriots on both sides of the Taiwan Strait,” said Zhu Fenglian, a spokesperson for the government's Taiwan Affairs Office.

The Taiwan Strait is a 160-kilometre-wide body of water between China and the island of Taiwan.

China's military held major exercises around Taiwan following both Lai's inauguration in May and his national day speech in October. It also held a major drill after Nancy Pelosi, then the speaker of the US House of Representatives, visited Taiwan in 2022.