China has ratcheted up military and political pressure on self-ruled Taiwan since President Tsai Ing-wen came to power in 2016 because she rejects Beijing's stance that the island is part of Chinese territory.

"The People's Liberation Army's continuous military harassment in the region could lead to a sharp escalation of tensions and worsening of regional security," Taiwan's Defence Ministry said in a statement.

"We urge Beijing to take responsibility and immediately cease all unilateral actions that undermine regional stability," it said.

According to the ministry, Beijing had sent 24 aircraft, including fighter jets, bombers and drones, as well as five warships close to Taiwan in what it described as a "joint combat patrol" since 9 am local time (0100 GMT).

Half the warplanes crossed the median line of the Taiwan Strait or entered the self-ruled island's southwest air defence identification zone (ADIZ), it said, and Taipei was using its own aircraft, vessels and land-based missile systems to monitor them.

Taipei has seen an increase in Chinese air incursions since Tsai's visit to Eswatini, the only African country that recognises Taiwan diplomatically over China, was announced on Friday.

The defence ministry said on Saturday it had detected 32 Chinese warplanes and nine warships around the island over 24 hours.

The increase in incursions also comes after the United States approved last week the sale to Taiwan of advanced sensor equipment for fighter jets.

And on Monday, Taiwan's defence ministry said a Chinese BZK-005 drone circled the island on a flight path that appears to be increasingly common for such long-range vehicles.

Beijing conducted military exercises to simulate the encirclement of the island in April after Tsai met US House Speaker Kevin McCarthy in California.

Beijing also staged military drills earlier this month after Vice President Lai Ching-te made returned to Taiwan after a trip to Paraguay that included two US stopovers, and banned mango imports from the island.

China's state-run Xinhua news agency said the drills were intended to serve as "a stern warning to the collusion of 'Taiwan independence' separatists with foreign elements and their provocations".