The US President Donald Trump has said the Covid-19 outbreak had hit the country harder than the Japanese bombing of Pearl Harbor in World War Two, or the 9/11 attacks two decades ago, pointing the finger at China.
His administration is weighing punitive actions against China over its early handling of the global emergency, BBC reported.
Beijing says the US wants to distract from its own response to the pandemic.
Since emerging in the Chinese city of Wuhan in December, the coronavirus is confirmed to have infected 1.2 million Americans, killing more than 73,000.
What did President Trump say?
Speaking to reporters in the Oval Office of the White House on Wednesday, Mr Trump said: "We went through the worst attack we've ever had on our country, this is worst attack we've ever had.
"This is worse than Pearl Harbor, this is worse than the World Trade Center. There's never been an attack like this.
"And it should have never happened. Could've been stopped at the source. Could've been stopped in China. It should've been stopped right at the source. And it wasn't."
Asked later by a reporter if he saw the pandemic as an actual act of war, Trump indicated the outbreak was America's foe, rather than China.
"I view the invisible enemy [coronavirus] as a war," he said. "I don't like how it got here, because it could have been stopped, but no, I view the invisible enemy like a war."
Who else in Trump's team is criticising China?
The deepening rift between Washington and Beijing was further underscored on Wednesday as Secretary of State Mike Pompeo renewed his rhetoric against China, accusing it of covering up the outbreak.
He stuck by his so far unsubstantiated charge that there is "enormous evidence" the coronavirus hatched in a Chinese laboratory, even while acknowledging there is still uncertainty about its origins.
"Those statements are both true," America's top diplomat told the BBC. "We don't have certainty and there is significant evidence that it came from a lab."
Chinese state media accused him of lying.
One of the most trusted US public health experts has said the best evidence indicates the virus was not made in a lab.
Dr Anthony Fauci, a member of Trump's coronavirus task force, said on Monday the illness appeared to have "evolved in nature and then jumped species".
Why is the US blaming China?
President Trump faces a tough re-election campaign in November, but the once humming US economy - which had been his main selling point - is currently in a coronavirus-induced coma.
A Pew opinion survey last month found that two-thirds of Americans, a historic high, view China unfavourably. But roughly the same margin of poll respondents said they believed Mr Trump acted too slowly to contain the pandemic.
As Trump found his management of the crisis under scrutiny, he began labelling the outbreak "the China virus", but dropped that term last month days before speaking by phone with Chinese President Xi Jinping.
Both Trump and his likely Democratic challenger, Joe Biden, appear to be fastening on to China's unpopularity as an election issue, with each accusing the other of being a patsy for America's primary economic competitor.
As the coronavirus began spreading in the US back in January, Trump signed phase one of a trade deal with China that called a truce in their tariff war. The US president's hopes of sealing a more comprehensive phase two deal are now in limbo because of the pandemic.