The administration of Donald Trump announced new travel and health screening measures on Monday in response to a growing Ebola outbreak in Central Africa that has killed more than 130 people.

Under the new restrictions, people who do not hold U.S. passports will be barred from entering the United States if they have recently traveled to the Democratic Republic of the Congo, Uganda or South Sudan within the past 21 days.

The measures were announced by the Centers for Disease Control and Prevention, which also said enhanced health screening would be introduced for travelers arriving from affected areas.

Health officials in Congo say at least 131 people are believed to have died in the latest outbreak. Congo’s health minister, Samuel Roger Kamba, confirmed the figure on Tuesday. Neighboring Uganda has also reported one death linked to the outbreak, according to the Africa Centres for Disease Control and Prevention.

The CDC said the new rules take effect immediately and will remain in place for at least 30 days. The restrictions do not apply to U.S. citizens, permanent residents or American military personnel.