China must be more honest about the origins of the COVID-19 pandemic, the U.S. ambassador to China said on Monday, after reports that the U.S. Energy Department concluded the pandemic likely arose from a Chinese laboratory leak.

Nicholas Burns, speaking by video link at a U.S. Chamber of Commerce event, said it was necessary to push China to take a more active role in the World Health Organization (WHO) if the U.N. health agency was to be strengthened.

China also needed to "be more honest about what happened three years ago in Wuhan with the origin of the COVID-19 crisis," Burns said, referring to the central Chinese city where the first human cases were reported in December 2019.