Twenty-one people on board a mammoth cruise ship off the California coast have tested positive for the coronavirus, including 19 crew members, Vice President Mike Pence has announced.
Federal officials have been working with the state and “we have developed a plan to bring the ship to a non-commercial port,” Mr Pence said.
“All passengers and crew will be tested for the virus. Those that will need to be quarantined will be quarantined. Those who will require medical help will receive it.”
Princess Cruises said 45 of the more than 3,500 people on board, which includes 140 Britons, were tested in the first round.
A military helicopter crew lowered test kits on to the 951ft Grand Princess by rope on Thursday and later retrieved them for analysis as the vessel waited off San Francisco, under orders to keep its distance from shore.
US President Donald Trump, speaking at the US Centres for Disease Control and Prevention in Atlanta, said he would have preferred not to let the passengers disembark onto American soil but will defer to the recommendations of medical experts.
He said: “I don’t need to have the numbers double because of one ship that wasn’t our fault.
“And it wasn’t the fault of the people on the ship either. Okay? It wasn’t their fault either. And they are mostly Americans.”
Health officials trying to establish whether the virus is circulating on the Grand Princess undertook the testing after reporting that a passenger on a previous voyage of the ship, in February, died of the disease.
In the past few days, health authorities disclosed that at least nine other people who were on the same journey were also found to be infected. Some passengers on that trip stayed aboard for the current voyage.
“The ship will not come on shore until we appropriately assess the passengers,” California Governor Gavin Newsom said on Thursday.
Another Princess cruise ship, the Diamond Princess, was quarantined for two weeks in Yokohama, Japan, last month because of the virus, and ultimately about 700 of the 3,700 people aboard became infected in what experts pronounced a public health failure, with the vessel essentially becoming a floating germ factory.