New York, Connecticut and New Jersey will require visitors from states with high coronavirus infection rates to quarantine for 14 days upon arrival, beginning Thursday, the three governors said.

“We now have to make sure the rates continue to drop," New York Gov. Andrew Cuomo said Wednesday at a video briefing with Govs. Phil Murphy of New Jersey and Ned Lamont of Connecticut, both fellow Democrats. “We also have to make sure the virus doesn’t come on a plane again.”

What was presented as a “travel advisory” affects three adjacent Northeastern states that after time were able to check the spread of the virus this spring as New York City became a hot spot for the pandemic.

The quarantine is voluntary but “urgent guidance,” Lamont said at a briefing in Hartford, noting it will be enforced differently in each state. Connecticut is considering putting up signs at entry points and getting the word out via social media.

As of Wednesday, states over the threshold were Alabama, Arkansas, Arizona, Florida, North Carolina, South Carolina, Washington, Utah and Texas.