Trump says he will meet with leaders of big pharmaceutical groups at the White House on Monday to discuss treatments and efforts to develop a vaccine to combat the virus, AFP reported.

The president said the number of cases detected by the US public health system now stood at 22. Combined with patients who were repatriated from abroad, the overall number of infected on US soil is now about 70.

"We will see more cases," Health Secretary Alex Azar told the White House press conference.

"But it's important to remember, for the vast majority of individuals who contract the novel coronavirus, they will experience mild to moderate symptoms."

Their treatment will be to remain at home and treat the symptoms as they would the flu, he added.