Taiwan scrambled jets today to warn away 20 Chinese aircraft, including 14 that crossed the Taiwan Strait median line, Taiwan's defence ministry said.

It also detected 14 Chinese military ships conducting activities around the Taiwan Strait, the ministry said in a statement.

Earlier, Taiwan accused the Chinese army of simulating an attack on its main island, as the Beijing government continued its retaliation for US House Speaker Nancy Pelosi's Taipei visit.

Relations between the two superpowers nosedived following Ms Pelosi's trip to China's self-ruled neighbour - which it claims as its territory - prompting calls from the United Nations for an urgent de-escalation of tensions.

China has maintained some of its largest-ever military drills around Taiwan - exercises aimed at practising a blockade and ultimate invasion of the island, analysts say.

The Taiwanese government said it observed "multiple batches" of Chinese planes and ships operating in the Taiwan Strait, some of which crossed a demarcation line that divides the strait, but which China does not recognise.

"They were judged to be conducting a simulation of an attack on Taiwan's main island," it said.

The democratic island's military mobilised air and land patrols and deployed land-based missile systems in response, the defence ministry said in a tweet.

Earlier, US Secretary of State Antony Blinken accused China of "irresponsible steps" by halting key communication channels with Washington, and said its Taiwan actions showed a move from prioritising peaceful resolution towards use of force.

China's retaliation in stopping bilateral processes in eight key areas including defence, narcotics, transnational crime and climate change were moves that would punish the world, not just the United States, Mr Blinken told a news conference in Manila in the Philippines.

US Secretary of State Antony Blinken was speaking in Manila

"Those include several military to military channels, which are vital for avoiding miscommunication and avoid crisis," he said.

"Suspending climate cooperation doesn't punish the United States, it punishes the world, particularly the developing world. We should not hold hostage cooperation on matters of global concern because of differences between our two countries."

Tackling climate change has been a key area of cooperation between the two superpowers and two biggest emitters of greenhouse gas emissions.

Mr Blinken said the United States had been hearing concern from allies about what he called China's dangerous and destabilising actions around Taiwan, but the US would remain steady in its handling of the situation.

He said he had conveyed to China's Foreign Minister Wang Yi at a regional meeting in Cambodia that the United States was determined to keep communication channels going to prevent miscalculations, as countries around the world expected them to.

"So let me be clear, the United States doesn't believe that it's in the interest of Taiwan, the region, or our own national security to escalate the situation," he said.

"We'll keep our channels of communication with China open, with the intent of avoiding escalation due to misunderstanding or miscommunication."

He added: "Maintaining dialogue is arguably even more important when we're in a period of heightened tensions ... We seek to deescalate those tensions. And we think dialogue is a very important element of that."