US President Trump has appointed his Vice President Mike Pence to coordinate the government response to the coronavirus outbreak.
Both men told a White House news conference that the risk to the American people remained very low.
The announcement came as new cases of Covid-19, the infection caused by the Wuhan coronavirus, continue to spread at a rapid pace around the world.
Sixty cases have so far been reported in the US.
Minutes after the White House news conference, the authorities confirmed another US case of Covid-19 – the first to occur on US soil.
The unidentified person in California had “no relevant travel history or exposure to another known patient” with the virus, the Centers for Disease Control said.
Addressing the press, Mr Trump expressed confidence that the US would be able to handle coronavirus.
“We’re very, very ready for this,” Mr Trump said. Researchers were “rapidly developing” a vaccine, he said.
He credited decisions to limit certain flights into the US with containing the number of infections.
Director of the National Institute of Allergy and Infectious Diseases, Anthony Fauci, said he did not expect a vaccine to be ready for a year to a year-and-a-half at the earliest.
The US health secretary, Alex Azar, said the White House had developed a plan to focus on five priorities, including better disease surveillance, local government response coordination, developing therapeutics, and increasing manufacturing of personal health protection equipment, like masks.
More US cases are to be expected, Mr Azar said.