US President Donald Trump renewed his criticism of China over the global coronavirus pandemic and said it has been worse for the United States than Pearl Harbor and 9/11.
Mr Trump said fallout from the pandemic has hit the US harder than the 7 December, 1941 Japanese bombing of Pearl Harbor or the 11 September, 2001 al-Qaeda attacks on New York and Washington.
"This is really the worst attack we've ever had," Mr Trump told reporters at the White House.
"This is worse than Pearl Harbor. This is worse than the World Trade Center."
The surprise Japanese attack on the Pearl Harbor naval base in Hawaii drew the US into World War II.
The 9/11 attacks killed about 3,000 people, triggering two decades of US wars and anti-terrorism operations in Iraq, Afghanistan and other countries.
Mr Trump lashed out at China, continuing a war of words over the origins of the deadly virus that emerged in Wuhan last year.
"It should have never happened," he said. "Could have been stopped at the source. Could have been stopped in China."
China has hit back at US Secretary of State Mike Pompeo over his claims the virus originated in a Wuhan laboratory, saying he has no evidence.
"This matter should be handed to scientists and medical professionals, and not politicians who lie for their own domestic political ends," China's foreign ministry spokeswoman said.
Scientists believe the disease originated in animals and transferred to humans - possibly in a Wuhan wet market where wild animals were sold.
So far, more than 73,000 Americans have died of Covid-19, and the former director of the Centers for Disease Control and Prevention predicted the toll in the US could top 100,000 by the end of May.
Tom Frieden warned US politicians to brace for a "long and difficult" war and urged dramatically expanded testing.
"Until we have an effective vaccine, unless something unexpected happens, our viral enemy will be with us for many months or years," Mr Frieden said.
The pandemic has killed more than 260,000 people globally and officially infected nearly 3.7 million, although because of limited testing, the number is believed to be far higher.
Europe accounts for the lion's share of deaths and infections, though hardest hit the UK, Italy, Spain and France have seen a levelling off of new cases and fatalities.
