An illustration of the new coronavirus COVID-19. Image courtesy of the Centers for Disease Control.

Govs. Ned Lamont announced that travelers from Massachusetts must self-quarantine for 14 days after arriving in Connecticut.

At the same time, Gov. Andrew Cuomo strongly urged New York and Massachusetts residents not to cross the two states’ border, but stopped short of adding its neighboring state to New York’s official quarantine list.

Only seven states, including New York, have reported an average of fewer than 10 new cases per 100,000 residents over the past seven days.

The rest of the nation exceeds that threshold and qualifies for inclusion on New York’s travel advisory, which started as a joint effort this summer with Connecticut and New Jersey. Connecticut, New Jersey and Pennsylvania all now exceed the quarantine threshold.

Massachusetts’ average has reached 15.1.

But New York is not adding neighboring states to its official advisory list. Gov. Andrew Cuomo is instead urging New Yorkers to avoid traveling to the states for now, and says it’s not practical to enforce quarantine rules given the region’s interconnected nature.

New Jersey and Rhode Island meet the criteria for Connecticut’s travel advisory, however given the interconnected nature of the region and mode of transport between the states, Lamont’s office said in a statement, they are not being included on the list of states required for a mandatory quarantine. Lamont “highly discourages, to the extent practical,” all nonessential travel between the states, his office said.