The Obama administration will assign 3,000 U.S. military personnel to West Africa “to combat and contain” what senior administration officials call an “extraordinarily serious epidemic.”

This new assistance will supply medical and logistical support to overwhelmed local health care systems and increase the number of beds needed to isolate and treat victims of the Ebola crisis.

President Obama planned to announce the expanded effort Tuesday during a visit to the Centers for Disease Control and Prevention in Atlanta, amid alarm that the outbreak could spread. Officials fear the deadly virus could mutate into a more easily transmitted disease.