The White House has called on China to hand over data from the early stages of the coronavirus pandemic and expressed “deep concerns” about a World Health Organization fact-finding mission to Wuhan. After a four-week visit to Wuhan, the Chinese city where the pandemic is believed to have emerged, the WHO this week said it was “extremely unlikely” that the pathogen had leaked from a Chinese laboratory — a theory the Trump administration had promoted without providing evidence.

“We have deep concerns about the way in which the early findings of the Covid-19 investigation were communicated and questions about the process,” Jake Sullivan, national security adviser, said on Saturday. The criticism came after the Wall Street Journal reported that some WHO experts said China had not provided raw data related to a possible outbreak earlier than December 2019 in another part of China.

“China must make available its data from the earliest days of the outbreak,” Sullivan said in his statement. Aanalysis were needed to reach a more definitive conclusion about the origin of the virus. But he added that some of that work may lie “outside the remit and scope” of the four-week WHO mission to Wuhan.

During the Trump administration, Mike Pompeo, then secretary of state, said the virus may have escaped from the Wuhan Institute of Virology. After repeatedly accusing the WHO of bending to the will of China, Donald Trump withdrew the US from the organization.