A press conference on the official website of Ministry of Foreign Affairs of the People's Republic of China refutes the claim.
According to the Global News coverage of Dr Redfield testifying to the U.S. Congressional Committee on 11 March 2020, California congressman Harley Rouda asked him questions about the detection of COVID-19 in Influenza patients, dead or alive, with the help of coronavirus test-kits. Dr Redfield answered that it was standard procedure to test patients for Influenza first and affirmed that it would only be diagnosed as such when people are tested.
Information on the CDC website shows that the weekly Influenza Surveillance report genetically characterised 2,065 influenza viruses collected in the U.S. from 29 September 2019 to 7 March 2020.
As per the press release by the Chinese Ministry of Foreign Affairs dated 13 March 2020, official spokesperson Lijian Zhao replied to a press question about whether the epidemic was brought to China by the U.S. Army by saying that there have been different opinions in the U.S. about the origin of the virus. He added that China believed it to be a matter of science which required professional and science-based assessment.
However, there is no scientific evidence to prove that the origin of the virus is from the U.S. The spokesperson's tweet is also inconsistent with the CDC's testification which was about the detection of the COVID-19 within the country in and around the first week of March 2020.
The COVID-19 pandemic has given rise to a lot of potentially dangerous misinformation. For reliable advice on COVID-19 including symptoms, prevention and available treatment, please refer to the World Health Organisation or your national healthcare authority.