Federal health authorities have revealed they now expect a wider spread of the new coronavirus in the U.S. and are preparing for a potential pandemic, though they still are unsure about how severe the health threat could be. On Tuesday, Dr. Nancy Messonnier, the head of the Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases division, said that Americans should prepare for the possibility of potential disruptions in connection with the coronavirus.

Dr. Messonnier explained that the CDC’s concern level has risen recently due to the coronavirus’ impact in other countries, particular most recently in Italy & Europe.

“It’s not so much a question of if this will happen any more, but rather more a question of exactly when this will happen and how many people in this country will have severe illness,” Dr. Messonnier said during a press conference on Tuesday, per NBC News.

While Dr. Messonnier reiterated that the current risk in the U.S. remains low, with the bulk of confirmed cases having occurred among travelers who were infected overseas, she still urged for preparatory measures to be taken seriously.

For recommendations on prevention and treatment, click here for the updated CDC guide.