The United States on Wednesday surpassed 400,000 novel coronavirus cases, according to a tally kept by Johns Hopkins University.
The pandemic has now claimed the lives of at least 12,936 people in the United States, which leads the world in the number of confirmed infections with 401,116, by the Baltimore-based school's count.
The 300,000-case milestone was passed on Saturday.
The US death toll is approaching those of hard-hit Italy with more than 17,000 and Spain with more than 14,500.
President Donald Trump has defended his response to the crisis, and on Tuesday he accused the World Health Organization of reacting slowly.
He questioned why the WHO had given "such a faulty recommendation," apparently referring to the UN body's advice against curtailing international travel to stop the virus which first spread from China.
"They called it wrong. They really missed the call. They could have called it months earlier," he said.
Trump has been widely criticized for initially downplaying the virus, which he likened to an ordinary flu and said was under control in the United States, before later accepting that it was a national emergency.