Yang‘s remarks were made after the US State Department summoned the Chinese Ambassador to the US Cui Tiankai over Chinese Foreign Ministry spokesperson Zhao Lijian‘s recent tweets.
In his tweets, Zhao claimed it might be US army representatives who brought the novel coronavirus to Wuhan, Central China‘s Hubei Province in October 2019, after a top US health official admitted detecting coronavirus infections on some deceased flu patients. Zhao urged the US to disclose further information, exercise transparency on coronavirus cases and provide an explanation to the public.