U.S. Speaker Nancy Pelosi arrives in Taiwan for official visit heavily criticized by China

U.S. House Speaker Nancy Pelosi arrived in Taiwan on Tuesday, an official visit sure to escalate tensions with Beijing, which claims the self-ruled island as its own territory.

The plane carrying Pelosi and her delegation took off from a Malaysian air force base and landed in Taipei on Tuesday night just before 11 p.m. local time. The United Daily News, Liberty Times and China Times — Taiwan's three largest national newspapers — cited unidentified sources as saying she would spend the night in Taiwan.

Pelosi, head of one of three branches of the U.S. government, is the highest-ranking elected American official to visit Taiwan since then-speaker Newt Gingrich in 1997.

Premier Su Tseng-chang didn't explicitly confirm Pelosi's visit, but said Tuesday that "any foreign guests and friendly lawmakers" are "very much welcome."

China had warned of "resolute and strong measures" if Pelosi went ahead with the trip. China's Defence 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."

Chinese Foreign Minister Wang Yi said Washington's meddling "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.

Shortly before Pelosi was due to arrive, Chinese state media said Chinese SU-35 fighter jets were "crossing" the Taiwan Strait, the body of water that separates mainland China and Taiwan. It wasn't immediately clear where they were headed or what they planned to do, and the Taiwanese government said the report was false.

Unspecified hackers launched a cyberattack on the Taiwanese Presidential Office's website, making it temporarily unavailable Tuesday evening. The Presidential Office said the website was restored shortly after the attack, which overwhelmed it with traffic.

U.S. Secretary of State Antony Blinken urged China to "act responsibly" ahead of Pelosi's visit, which was not at the behest of the Biden administration.

White House National Security Council spokesperson John Kirby on Monday noted that members of Congress have routinely visited the island over the years — in April, Sen. Lindsey Graham led a delegation of six lawmakers from both parties to Taiwan, while the U.S. health secretary at the time visited in 2020.

U.S. officials have said the U.S. military would increase its movement of forces and assets in the Indo-Pacific region. Four U.S. warships, including an aircraft carrier, were positioned in waters east of Taiwan on what the U.S. Navy called routine deployments, a U.S. Navy official told Reuters on Tuesday.

Taiwan and China split in 1949 after the Communists won a civil war on the mainland.

The U.S. maintains informal relations and defence ties with Taiwan even as it recognizes Beijing as the government of China. The 1979 Taiwan Relations Act, which has governed U.S. relations with the island, does not require the U.S. to step in militarily if China invades, but makes it American policy to ensure Taiwan has the resources to defend itself and to prevent any unilateral change of status by Beijing.