Washington — Chinese Ambassador to the United States Cui Tiankai rebuked claims about the origins of the coronavirus, calling any theories it is linked to biological weapons research "absolutely crazy" and warning such allegations could stir up racial discrimination and xenophobia.

"I think it's true that a lot is still unknown and our scientists — Chinese scientists, American scientists, scientists of other countries — are doing their best to learn more about the virus," Cui said Sunday on "Face the Nation." "But it's very harmful, it's very dangerous to stir up suspicion, rumors and spread them among the people. For one thing, this will create panic. Another thing, that it will fan up racial discrimination, xenophobia, all these things, that will really harm our joint efforts to combat the virus."

Cui was responding to an assertion from Republican Senator Tom Cotton of Arkansas, who tweeted late last month that Wuhan, the city where the deadly outbreak started, "has China's only biosafety level-four super laboratory that works with the world's most deadly pathogens to include, yes, coronavirus."

Cotton has harshly criticized Beijing's handling of the outbreak for weeks. His allegation joined other theories — that have been largely debunked by experts — that the virus may be tied to the Wuhan National Biosafety Laboratory and could have come from China's biological warfare program.

Cui said that charge is "absolutely crazy" and noted while the Chinese government still doesn't know where the coronavirus originated, initial research indicates it came from animals.

"Of course, there are all kinds of speculation and rumors," he said. "There are people who are saying that these viruses are coming from some military lab, not of China, maybe in the United States. How can we believe all these crazy things?"

China's National Health Commission reported Sunday there have been 811 deaths in China from the coronavirus and 37,198 confirmed cases.

In the United States, the Centers for Disease Control has reported 12 confirmed cases in six states. The U.S. Embassy in Beijing on Saturday confirmed what appears to be the first death of an American from the disease, saying a 60-year-old U.S. citizen died in a hospital in Wuhan on February 6.