Chinese aircraft and warships have practised for an attack on Taiwan, island officials say, in retaliation for a visit there by US House Speaker Nancy Pelosi.
Pelosi's brief visit during the week to the self-ruled island that China regards as its territory infuriated Beijing and has prompted unprecedented military drills that have included ballistic missiles fired over the capital, Taipei.
US Secretary of State Antony Blinken accused China of taking "irresponsible steps" by halting key communication channels with Washington, and said its actions over Taiwan showed a move from prioritising peaceful resolution towards use of force.
Taiwan's defence ministry said multiple Chinese ships and planes conducted missions in the Taiwan Strait, with some crossing the median line, an unofficial buffer separating the two sides.
Taiwan's military described it as part of a simulation attack on the main Taiwan island.
The ministry said later that Taiwan scrambled jets to warn away 20 Chinese aircraft, including 14 that crossed the median line.
It also detected 14 Chinese military ships conducting activities around the Taiwan Strait, the ministry said in a statement.
China's Eastern Theatre Command said it had continued to conduct sea and air joint exercises north, southwest and east of Taiwan. It said its focus was on testing the system's land strike and sea assault capabilities.
The Chinese exercises - centred on six locations around the island - began on Thursday and are scheduled to last until midday on Sunday.
Taiwan's army broadcast a warning and deployed air reconnaissance patrol forces and ships to monitor while putting shore-based missiles on stand-by.
Taiwan's defence ministry also said it fired flares late on Friday to warn away seven drones flying over its Kinmen islands and unidentified aircraft flying over its Matsu islands.
"China's military drills have unilaterally changed the current situation in the region and seriously damaged the peace in the Taiwan Strait," the Taiwan defence ministry said.
Pelosi arrived in Taiwan late on Tuesday, the highest-level visit to the island by a US official in decades, despite Chinese warnings.
Shortly after her delegation left Japan on Friday, the final stop of a week-long Asia tour, China announced it was halting dialogue with the United States in a number of areas including between theatre-level military commanders and on climate change.
Speaking during a visit to the Philippines, Blinken said the US had been hearing concern from allies about what he called China's dangerous and destabilising actions around Taiwan.
Washington would remain steady in its handling of the situation and sought to avoid escalating the situation, he said.
China's foreign minister Wang Yi told a media briefing on Friday that Blinken was spreading "misinformation", adding: "We wish to issue a warning to the United States: Do not act rashly, do not create a greater crisis."
Australian Associated Press
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