The U.S. says Americans aboard a quarantined cruise ship will be flown back home on a chartered flight Sunday.About 380 Americans are aboard the Diamond Princess cruise ship, which has docked at Yokohama, a port city southwest of Tokyo. So far, 285 people from the ship have tested positive for a new virus, after 67 new cases were found Saturday.

The aircraft will arrive in Japan late Sunday, and people will be flown to Travis Air Force Base in California, with some passengers continuing to Lackland Air Force Base in Texas, the U.S. Embassy in Tokyo said in a letter to passengers and crew that was posted online Saturday.

Everyone will get a checkup before being allowed on the chartered flight, and those who show symptoms of sickness will not be permitted to board the plane, the embassy said.

“We recognize this has been a stressful experience and we remain dedicated to providing all the support we can and seeing you safely and expeditiously reunited with family and friends in the United States,” it said.

“To fulfill our government’s responsibilities to U.S. citizens under our rules and practices, as well as to reduce the burden on the Japanese healthcare system, the U.S. government recommends, out of an abundance of caution, that U.S. citizens disembark and return to the United States for further monitoring,” the State Department said in a statement.

One of the American passengers, Matthew Smith, who has been tweeting aboard the ship, including photos of the food passengers have been given, expressed disappointment at what he called “a monkey wrench” the American government was throwing into the quarantine that he and others had tried to maintain on the ship.

The letter to Americans on the Diamond Princess warns, “Should you choose not to return on this charter flight, you will be unable to return to the United States for a period of time.”