Chinese Foreign Ministry spokesman Zhao Lijian on July 26 urged the U.S. to answer the call from over 13 million Chinese netizens, who have signed an online petition calling on the World Health Organization (WHO) to investigate the Fort Detrick lab in Maryland, U.S., for COVID-19 origin tracing. 

The petition is a joint open letter published on July 17, appealing to the WHO to investigate the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, and urging the U.S. to answer to the call from people around the world.