In response to Washington's accusation of a cover-up, China's Foreign Ministry Spokeswoman Hua Chunying said on Thursday that China first notified the US government about the novel coronavirus on January 3.

(File photo: Hua Chunying)

"China has been updating the US on the coronavirus and its response since Jan. 3. On Jan. 15 the US State Department notified Americans in China US CDC's warning about the coronavirus. And now blame China for delay? Seriously?" Hua Chunying said in a tweet.

The remarks came after US National Security Adviser Robert O'Brien accused China of covering up information about the outbreak and delaying global response.