The Centers for Disease Control and Prevention announced Monday that it will be implementing a 30-day ban on foreign travelers from countries affected by a growing Ebola outbreak.

The order from the CDC invokes Title 42, which allows the agency director to block noncitizens from entering the U.S. for public health purposes for up to 30 days. Travelers with foreign passports will be barred from entering the U.S. if they have been in the Democratic Republic of the Congo, Uganda or South Sudan within the past 21 days.

U.S. citizens who traveled to the affected countries will also be subject to enhanced screenings, authorities said.

On a call with reporters Monday, Dr. Satish Pillai, the Ebola-response incident manager for the CDC, said the agency is “coordinating with airlines and international partners” and taking a variety of steps to keep infected individuals from entering the country.

Pillai also confirmed there is one case of Ebola in an American, who was exposed in Congo.

“The person developed symptoms over the weekend and tested positive late Sunday,” Pillai said. “CDC has been working hand in hand with the Department of State to move the American for treatment and care to Germany and other high-risk contacts to Germany for monitoring, given the previous experience for caring for Ebola patients.”

The Infectious Diseases Society of America, a global community of 13,000-plus clinicians, scientists and public health experts, criticized the move by the CDC for singling out non-U.S. citizens.

“Diseases don’t recognize passports,” Jeanne Marrazzo, the group’s CEO, said in a statement. “The United States needs to make a sustained investment in public health and research for preventing, monitoring and responding to infectious diseases here and abroad. We also need respectful, expert coordination with peers across the globe.”

The order from the CDC comes after the World Health Organization declared the Ebola outbreak a global health emergency.

According to the CDC, this is the 17th Ebola outbreak in Congo since 1976 and the country’s second outbreak of the Bundibugyo virus — one of several viruses that can cause Ebola disease in humans. As of Monday, the CDC says there have been reports of 10 confirmed cases and 336 suspected cases, including 88 deaths, in Congo and two confirmed cases, including one death, in Uganda.

The outbreak is also likely to complicate preparations for the U.S.-hosted FIFA World Cup starting next month. Prior to the travel ban being announced, a team from Congo was set to begin play in Houston.

When asked by reporters about how the CDC will handle the World Cup and Congo’s participation, Pillai said it’s “an evolving situation.”

“We’re going to continue to work with our interagency colleagues to lock down the final plans on that, so more to follow,” Pillai said.