The U.S. government made good on its warning to Americans who chose to remain on board a quarantined cruise ship in Japan, telling them they cannot return home for at least two weeks after they come ashore.

U.S. officials notified the passengers Tuesday of the travel restriction, citing their possible exposure to the new virus while on board the Diamond Princess. More than 100 U.S. citizens are still on the ship or in Japanese hospitals.

A two-week quarantine of the Diamond Princess ends Wednesday. Over the weekend, more than 300 American passengers, including some who tested positive for coronavirus, left Japan on charter flights. Most of them remain under quarantine at military bases in California and Texas, although about a dozen have been moved to a hospital.

Some Americans decided to take their chances and stay on the ship. On Tuesday, they were told their names would be put on a travel restriction list. The letter from U.S. health authorities said the passengers would not be issued a boarding pass or allowed on a flight “until you are no longer at risk of spreading infection during travel.”

The letter also warned them against trying to enter the country through Mexico or Canada or at a seaport, saying “you will be stopped by U.S. Customs and Border Protection officials.”

———

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.