US President Donald Trump on Wednesday sought to downplay fears of the coronavirus threat in the United States, saying the risk remained "very low" and it was "not inevitable" that the novel virus would spread further in the country, which has reported 60 confirmed cases.

But he elevated Vice-President Mike Pence to take charge of the US response to a contagion that has spread to about three dozen countries, with a total caseload exceeding 81,000.

"The risk to the American people remains very low," Trump, flanked by Pence and public health officials, told reporters in a packed James Brady Briefing Room at the White House. 

"We're ready to adapt and we're ready to do whatever we have to as the disease spreads, if it spreads," he said.

"I don't think it's inevitable," Trump said of the spread of the virus, in apparent contradiction of officials from the Centers for Disease Control and Prevention, who said a day earlier that the spread of the disease in the US is inevitable.

"It probably will, it possibly will. It could be at a very small level, or it could be at a larger level. Whatever happens, we're totally prepared," Trump said.

Trump showed a chart made by the Johns Hopkins experts that ranked the US at the top among countries in preparedness for the novel coronavirus epidemic.

"This will end," Trump said of the outbreak. "You don't want to see panic because there's no reason to be panicked."

The president even offered tips for people worried about COVID-19.

"Wash your hands, stay clean. You don't have to necessarily grab every handrail unless you have to," Trump said. "When somebody sneezes, I try to bail out."

But Dr Anne Schuchat of the CDC said, "We do expect more cases."

The Trump administration had requested $2.5 billion from Congress to fight the virus. But some lawmakers, believing that the request is insufficient, had countered with proposals for more spending.

Trump told reporters he would accept "whatever's appropriate".