It was a tragedy for anyone hoping to see COVID-19 become a catalyst for international solidarity. On the first day of the first-ever virtual World Health Assembly, held during the worst acute global health crisis since WHO's creation in 1948, Alex Azar, US Secretary of Health and Human Services, further damaged the credibility of the US Government as a constructive member of the international community. “We must be frank”, he began. What followed was an astonishing series of unsubstantiated allegations. “There was a failure by this organisation”, Azar stated. He argued that WHO had conspired with a member state (he meant China) “in an apparent attempt to conceal this outbreak”. He accused WHO of unjustly blocking Taiwan's participation at the World Health Assembly. And he said “WHO must change.” It must be more transparent and more accountable. Earlier, WHO Director-General Tedros Adhanom Ghebreyesus gave a forceful defence of the agency. He accepted that “we all have lessons to learn”, but argued that WHO had stood “shoulder-to-shoulder with countries”. The agency had acted quickly, Tedros said. He promised to initiate an “independent evaluation” of the global response. “The world must never be the same.” There was no need for new plans, procedures, or institutions. What mattered now was to strengthen existing mechanisms, especially national public health capacities specified in the 2005 International Health Regulations. Investing in health was a prerequisite for development. To protect the world from future pandemics, Tedros called on member states to support a stronger WHO. In the speeches that followed, countries repeatedly backed WHO and the Director-General. China stressed that it acted in a timely, open, transparent, and responsible manner. Some countries went further, denouncing the unilateral and coercive actions of the US Government. That was on Monday. Overnight, President Trump wrote an explosive letter to WHO's Director-General. He claimed that “the repeated missteps by you and your organization in responding to the pandemic have been extremely costly to the world…if the World Health Organization does not commit to major substantive improvements within the next 30 days, I will make my temporary freeze of United States funding to the World Health Organization permanent and reconsider our membership in the organization. I cannot allow American taxpayer dollars to continue to finance an organization that, in its present state, is so clearly not serving America's interests.” But the basis for his accusations is dubious at best. In his letter, President Trump reports the results of a review his administration conducted into WHO's response to the COVID-19 pandemic. He wrote that “we know the following”. The first allegation he makes is that WHO “consistently ignored credible reports of the virus spreading in Wuhan in early December 2019 or even earlier, including reports from the Lancet medical journal. The World Health Organization failed to independently investigate credible reports that conflicted directly with the Chinese government's official accounts, even those that came from sources within Wuhan itself.” This statement is factually incorrect. The Lancet published no report in December, 2019, referring to a virus or outbreak in Wuhan or anywhere else in China. The first reports the journal published were on Jan 24, 2020. In a paper by Chaolin Huang and colleagues, the first 41 patients from Wuhan with COVID-19 were described. The scientists and physicians who led this study were all from Chinese institutions. They worked with us closely, collaboratively, and quickly to make information about this new epidemic outbreak and disease fully and freely available to an international audience. A second paper, from Jasper Fuk-Woo Chan and colleagues, also published on Jan 24, described the first scientific evidence confirming person-to-person transmission of the new virus. This report included scientists and physicians from Hong Kong and mainland China. The allegations levelled against WHO in President Trump's letter are serious and damaging to efforts to strengthen international cooperation to control this pandemic. It is essential that any review of the global response is based on a factually accurate account of what took place in December and January. It is regrettable that President Trump's letter fell short of these standards. He should retract his letter, correct the record, and withdraw his allegations against WHO.