Trump, who has been accused of peddling misinformation on the outbreak, blamed the media in a tweet for trying to make his government “look bad” as criticism mounted with nearly 500 cases recorded.

“We have a perfectly coordinated and fine tuned plan at the White House for our attack on CoronaVirus,” Trump tweeted.

“We moved VERY early to close borders to certain areas, which was a Godsend. V.P. is doing a great job. The Fake News Media is doing everything possible to make us look bad. Sad!”

But Larry Hogan, the Republican governor of Maryland, criticised Trump, telling NBC the president “hasn’t communicated the way I would, and the way I might like him to.”

New York governor Andrew Cuomo said federal health authorities had been “caught flat-footed” and had “handcuffed” the ability of individual states to respond.

“Their messages are all over the place, frankly,” he told Fox News.

Trump has been heavily rebuked for repeatedly contradicting the advice of his administration’s experts in his public pronouncements about the coronavirus.

He has downplayed the threat posed by the epidemic, which has killed more than 3,500 people since emerging in China, suggesting cases were “going very substantially down, not up,” falsely pledging that a vaccine would soon be available and claiming that the official estimate of the death rate was “false.”

From the start of February, the Trump administration focused on cutting off travel from China and imposing quarantines in an effort to keep the virus out of the United States.

Epidemiologists say the initial containment effort may have slowed the arrival of the virus but accuse the White House of wasting time with a strategy concerned more with the political narrative than domestic readiness.

Chief among the complaints has been the lack of testing caused by the Centres for Disease Control and Prevention (CDC) developing its own flawed kits, rather than using those approved by the World Health Organisation.

Meanwhile critics point to deep CDC cuts and the White House’s removal of a position on the National Security Council for responding to pandemics.

Oregon became the latest state to declare an emergency as the number of patients in the northwestern state rose to 14.

Governor Kate Brown said the measures to “unlock” key resources would remain in place for at least 60 days.

Officials reported that two people at the recent Conservative Political Action Conference attended by Trump and the administration’s coronavirus point man, Vice-President Mike Pence, had tested positive for the new coronavirus.

Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told NBC that officials were “accelerating dramatically” on coronavirus testing.

Defiant Trump refuses to halt rallies as coronavirus spreads in US

He told Fox News the possibility of following Italy’s example in locking down large sections of the population, or even entire cities, could not be ruled out.

“You don’t want to alarm people but, given the spread we’ve seen, anything is possible,” he said.

California prepared to disembark passengers from the Grand Princess, a virus-hit cruise ship with 21 novel coronavirus infections among the 3,500 people on board.

It is set to dock in Oakland on Monday after four days held off the coast of nearby San Francisco.

Passengers “will not be released into the general public” but will either be moved to hospitals for treatment or to federal “isolation facilities” in California, Texas and Georgia, officials said Sunday.

Several hundred foreign passengers will be repatriated to their countries.