Pelosi, who is second in line for the presidency, is set to visit the self-governing island claimed by China in August, according to a report in the Financial Times. He was originally scheduled to visit her in April, but had to postpone after testing positive for COVID-19. Pelosi would be the highest-ranking US lawmaker to visit the close US ally since her predecessor as speaker, Newt Gidrich, traveled there 25 years ago. China has vowed to annex Taiwan by force if necessary and has advertised that threat by flying warplanes near Taiwan’s airspace and conducting military exercises based on invasion scenarios. He says these actions are aimed at preventing the island’s supporters of formal independence and foreign allies – mainly the US – from helping it, more than 70 years after the sides split amid civil war. A visit by Pelosi “would seriously undermine China’s sovereignty and territorial integrity, seriously affect the foundations of China-US relations, and send a seriously wrong message to Taiwan independence forces,” Foreign Ministry spokesman Zhao Lijiang said in a Daily Briefing. “If the US persists in following the wrong path, China will take decisive and strong measures to safeguard its sovereignty and territorial integrity,” Zhao said. White House press secretary Karin Jean-Pierre declined to comment on Pelosi’s expected visit to Taiwan. Jean-Pierre said the United States’ support for Taiwan remains “unwavering,” while he reiterated the long-standing U.S. commitment to the “One China” policy that recognizes Beijing as China’s government but allows informal relations and defense ties with Taipei. China in recent days has also stepped up its rhetoric on US arms sales to Taiwan, demanding the cancellation of a deal worth about $108 million that would boost its armed forces’ chances of survival against its much larger foe. China has the world’s largest standing army, an increasingly sophisticated navy and a huge stockpile of missiles aimed at the 180-kilometer (100-mile) wide Taiwan Strait. “The Chinese People’s Liberation Army … will resolutely prevent any form of interference by outside forces and separatist plots for ‘Taiwan independence,’” the defense ministry said in a statement posted on its website on Tuesday. While Washington maintains a policy of “strategic ambiguity” on whether it would defend Taiwan in a conflict with China, US law requires it to ensure the island has the means to defend itself and to treat threats to its security as matters of “serious concern”. Washington maintains only informal relations with Taiwan out of deference to Beijing, but it is the island’s strongest political ally and source of defensive weapons. Zhao did not elaborate on possible actions China could take in response to Pelosi’s visit, but Beijing generally uses military flights and war games to show its displeasure. Chinese pilots have also been accused of aggressive action against surveillance aircraft by the US and its allies operating in international airspace off the Chinese coast, while using lasers and other methods to harass foreign warships in the South China Sea. China’s most serious threat against Taiwan came in 1995-96, when it held military exercises and fired missiles into waters north and south of the island in response to a visit to the US by then-President Lee Teng-hui.