A delegation of former senior U.S. defence and security officials sent by President Joe Biden arrived in Taipei on Tuesday on a visit denounced by China and happening in the midst of Russia's invasion of Ukraine.
The visit, led by one-time chairman of the Joint Chiefs of Staff Mike Mullen, comes at a time when Taiwan has stepped up its alert level, wary of China taking advantage of a distracted West to move against it.
Beijing claims the democratically governed island as its own and has vowed to bring it under Chinese control, by force if necessary.
Mullen, a retired Navy admiral who served as the top U.S. military officer under former presidents George W. Bush and Barack Obama, is being accompanied by Meghan O'Sullivan, a former deputy national security adviser under Bush, and Michele Flournoy, a former undersecretary of defense under Obama.
Two former National Security Council senior directors for Asia, Mike Green and Evan Medeiros, are also on the trip, which is intended to "demonstrate our continued robust support for Taiwan," a U.S. official told Reuters.
The group touched down in a private jet at Taipei's downtown Songshan airport and were met by Taiwan Foreign Minister Joseph Wu.
They will meet President Tsai Ing-wen on Wednesday, the same day former U.S. Secretary of State Mike Pompeo will also arrive, though he is coming separately and as a private citizen.
China describes Taiwan as the most sensitive and important issue in its ties with the United States, and any high-level interactions upset Beijing.
"The will of the Chinese people to defend our country's sovereignty and territorial integrity is immovable. Whoever United States sends to show support for Taiwan is bound to fail," Chinese Foreign Ministry spokesperson Wang Wenbin said of the visit.
Taiwan Premier Su Tseng-chang told reporters earlier on Tuesday that the trip showed "the importance both of the Taiwan-U.S. relationship and Taiwan's position" as well as the staunch U.S. support for the island.
"It's a very good thing," he added.
Their flight, from Washington via Anchorage, made an unusual arrival, flying down Japan's Ryukyu Islands before turning to approach Taipei from Taiwan's northeast coast and well away from China, data from flight tracking website FlightRadar24 showed.
The more normal approach path for their direction of travel is over the East China Sea.
On Saturday, a U.S. warship sailed through the sensitive Taiwan Strait, part of what the U.S. military calls routine activity but which China described as "provocative".
Wang went further on Tuesday, using even stronger terms.
"If United States is trying to threaten and pressure China with this then we need to tell them that in the face of the Great Wall of steel forged by 1.4 billion Chinese people, any military deterrence is but scrap metal," he said.
"The gimmick of having a U.S. warship sail through the Taiwan Strait should be left to those who foolishly believe in hegemony."
(Reporting by Yew Lun Tian and Ben Blanchard; Editing by Jacqueline Wong and Simon Cameron-Moore)
