The world needs the cooperation of the Chinese government to trace the origins of COVID-19 and prevent future pandemic threats, two leading U.S. disease experts said Sunday.

Information to support the theory that the SARS-CoV-2 virus may have escaped from a lab in Wuhan, China, has increased, said Scott Gottlieb, a commissioner of the Food and Drug Administration in the Trump administration who now sits on the board of Pfizer Inc.

China hasn’t provided evidence to disprove that theory, while the search for signs that the virus emerged from wildlife hasn’t yielded results, Gottlieb said on the CBS News program "Face the Nation.”