Joe Biden’s secretary of state, Antony Blinken, said on Sunday the US is concerned about China’s aggressive actions against Taiwan and warned it would be a “serious mistake” for anyone to try to change the status quo in the western Pacific by force. “What we’ve seen, and what is of real concern to us, is increasingly aggressive actions by the government in Beijing directed at Taiwan, raising tensions in the Straits,” Blinken told NBC’s Meet the Press. Blinken also said China’s failure to provide access to global health experts made the Covid-19 pandemic worse than it had to be, and it was important to “get to the bottom” of the origin of the novel coronavirus. Tensions between Washington and Beijing are high. On Thursday, China blamed the US for tensions after an American warship sailed close to Taiwan. On Friday the White House said it was keeping a close watch on increased Chinese military activities in the Taiwan Strait, and called Beijing’s actions potentially destabilizing. The US has a longstanding commitment to ensure that Taiwan has the ability to defend itself and to sustain peace and security in the western Pacific, Blinken said. Asked if the US would respond militarily to a Chinese action in Taiwan, Blinken declined to comment on a hypothetical. “All I can tell you is we have a serious commitment to Taiwan being able to defend itself,” he said. “We have a serious commitment to peace and security in the western Pacific. We stand behind those commitments. And in that context, it would be a serious mistake for anyone to try to change that status quo by force.“ Taiwan has complained of repeated missions by China’s air force near the island, which China claims. On Friday, the state department issued new guidelines that will enable US officials to meet more freely with officials from Taiwan, a move that deepens relations with Taipei amid stepped-up Chinese military activity. A state department spokesman, Ned Price, said the new guidelines followed a congressionally mandated review and would “provide clarity … on effective implementation of our ‘one China’ policy” – a reference to the longstanding US policy under which Washington officially recognizes Beijing rather than Taipei. Blinken’s sharp words about Covid-19, meanwhile, underscored criticism from other members of the Biden administration over Beijing’s lack of transparency in the crucial early days of the pandemic. China did not give access to international experts or share information in real time to provide true transparency, Blinken told NBC. As a result, the virus “got out of hand faster and with, I think, much more egregious results than it might otherwise,” Blinken said. The World Health Organization director-general, Tedros Adhanom Ghebreyesus, said on 30 March data was withheld from WHO investigators who traveled to China to research the origins of the pandemic. A WHO report, written jointly with Chinese scientists, said the virus had probably been transmitted from bats to humans through another animal, and that a lab leak was “extremely unlikely” as a cause. Tedros said the issue required further investigation. The events highlight why there needs to be a stronger global health security system to ensure this doesn’t happen again, Blinken said. Reforms must include a commitment to transparency, information sharing and access for experts “and China has to play a part in that”. Blinken said it was important to reach a more conclusive accounting of how the pandemic began. “We need to do that precisely so we fully understand what happened, in order to have the best shot possible preventing it from happening again,” he said. “That’s why we need to get to the bottom of this.” When the WHO report was issued in March, the US, the European Union and other western powers called for China to give “full access” to independent experts to all data about the original outbreak in late 2019.