(CNN) -- The U.S. State Department is urging Americans not to get on cruise ships as coronavirus cases rise across the United States.
is especially for people with underlying health conditions.
The is recommending people with such conditions "defer all cruise ship travel worldwide."
It said underlying conditions include heart disease, chronic lung disease, diabetes and conditions that suppress the immune system.
There are over 500 cases of coronavirus in the U.S.
Cruise Lines International Association said in , before the State Department's advisory, that restricting cruise ship travel is "unwarranted."
It said such restrictions contradict the World Health Organization's stance against travel or trade restrictions to countries experiencing an outbreak of the coronavirus.
