The State Department has chastised China’s ambassador to the US for Beijing’s insinuation that American service members might have brought the coronavirus to Wuhan.

David Stillwell, the top U.S. diplomat for East Asia, summoned China’s ambassador Cui Tiankai for the takedown. A State Department official told Reuters that Tiankai was “very defensive.”

China was seeking to deflect criticism of its role in “starting a global pandemic and not telling the world,” said the State Department official, who spoke on condition of anonymity.

“Spreading conspiracy theories is dangerous and ridiculous,” the official said. “We wanted to put the government on notice we won’t tolerate it for the good of the Chinese people and the world.”

China’s embassy did not respond to requests for comment.

On Friday, President Trump brushed aside a question about “odd narratives” from China. He said he had seen one report but didn’t think it was representative of his discussions with Chinese President Xi Jinping.

Trump called the outbreak a “foreign virus” that started in China during his prime-time address Wednesday, adding: “They know where it came from, we all know where it came from.”

On Thursday, Chinese Foreign Ministry spokesman Zhao Lijian tweeted criticisms of the U.S. in English, including, “When did patient zero begin in US? How many people are infected? What are the names of the hospitals? It might be US army who brought the epidemic to Wuhan. Be transparent! Make public your data! US owe us an explanation!”

The virus, also called COVID-19, has infected 145,000 people worldwide and killed more than 5,400. In the U.S., 2,174 people have been identified as infected and 47 have died, according to a database maintained by Johns Hopkins University. China, the hardest-hit country, has reported nearly 81,000 infections and almost 3,200 deaths.