US House Speaker Nancy Pelosi arrives in Taiwan

Nancy Pelosi speaks to reporters at her weekly press conference at the Capitol on August 22, 2020. [AFP]

U.S. House Speaker Nancy Pelosi arrived in Taiwan on Tuesday night despite threats from Beijing of serious consequences, becoming the highest-ranking American official in 25 years to visit the self-ruled island claimed by China.

Pelosi's visit has triggered increased tension between China and the United States. China claims Taiwan as part of its territory, to be annexed by force if necessary, and views visits by foreign government officials as recognition of the island's sovereignty.

China had warned of "resolute and strong measures" if Pelosi went ahead with the trip. China's Defense Ministry said Tuesday night it will conduct a series of targeted military operations to "safeguard national sovereignty" in response to Pelosi's visit. It vowed to "resolutely thwart external interference and 'Taiwan independence' separatist attempts."

The Biden administration did not explicitly urge Pelosi to call off the visit, while seeking to assure Beijing it would not signal any change in U.S. policy on Taiwan.

Chinese Foreign Minister Wang Yi said Washington's betrayal "on the Taiwan issue is bankrupting its national credibility."

"Some American politicians are playing with fire on the issue of Taiwan," Wang said in a statement. "This will definitely not have a good outcome ... the exposure of America's bullying face again shows it as the world's biggest saboteur of peace."

Pelosi said in a statement just after her arrival that the U.S. delegation's visit "honors America's unwavering commitment to supporting Taiwan's vibrant democracy."

"Our visit is one of several Congressional delegations to Taiwan -- and it in no way contradicts longstanding United States policy," she said.

The plane carrying Pelosi and her delegation left Malaysia earlier Tuesday after a brief stop that included a working lunch with Prime Minister Ismail Sabri Yaakob.

Taiwan's Foreign Ministry had declined to comment on whether Pelosi would visit. The trip was not officially announced ahead of time.

Barricades were erected outside the Grand Hyatt Hotel in Taipei where Pelosi was expected to stay amid heightened security. Two buildings in the capital lit up LED displays with words of welcome, including the iconic Taipei 101 building, which said "Welcome to Taiwan, Speaker Pelosi."

China, which regards Taiwan as a renegade province to be annexed by force if necessary, has repeatedly warned of retaliation for Pelosi's visit, saying its military will "never sit idly by."

"The U.S. and Taiwan have colluded to make provocations first, and China has only been compelled to act out of self-defense," Chinese Foreign Ministry spokesperson Hua Chunying told reporters Tuesday in Beijing.

Hua said China has been in constant communication with the U.S. and made clear "how dangerous it would be if the visit actually happens." Any countermeasures China take will be "justified and necessary" in the face of Washington's "unscrupulous behavior," she said.