WASHINGTON, D.C: The United States has expanded its temporary Ebola-related travel restrictions to include lawful permanent residents who have recently traveled to parts of East Africa, citing growing concerns about the spread of the virus.

The Centers for Disease Control and Prevention said on May 23 that Green Card holders who have been in the Democratic Republic of Congo, Uganda or South Sudan within the previous 21 days would now also face restrictions on entering the United States.

The move marks a significant expansion of the Ebola-related entry order first introduced earlier this week. Previously, U.S. citizens, nationals and lawful permanent residents had been exempt from the 30-day travel ban.

The CDC said the broader restrictions were necessary to reduce the risk of Ebola entering the country as health officials monitor an escalating outbreak linked to the rare Bundibugyo strain of the virus.

"Applying this authority to lawful permanent residents for a limited period of time provides a balance between protecting public health and managing emergency response resources," the CDC said in a statement.

The World Health Organization raised its assessment of the outbreak risk in the Democratic Republic of Congo to "very high" at the national level and declared the outbreak in Congo and neighboring Uganda a public health emergency of international concern.

Health experts have expressed concern because the Bundibugyo strain has no approved vaccine and because the outbreak appears to have circulated undetected for weeks in densely populated areas before being officially identified.

The CDC first issued the entry restrictions on Monday under Title 42 of U.S. public health law, which allows federal health authorities to prohibit migrants or travelers from entering the country to prevent the spread of contagious diseases.

Title 42 became widely known during the COVID-19 pandemic, when it was used to rapidly expel migrants at the U.S.-Mexico border on public health grounds.

However, lawful permanent residents have historically been exempt from most such restrictions. The COVID-era Title 42 order did not apply to Green Card holders, nor did several travel bans introduced during President Donald Trump's earlier administration.

The latest decision therefore represents an unusual step by extending the restrictions to permanent residents, even if temporarily.

The WHO and health authorities are continuing efforts to trace infections and contain the outbreak in Central and East Africa. Earlier this week, WHO officials said the outbreak had likely been spreading for nearly two months before being detected.

The United States has also announced additional funding and support for Ebola response efforts in the affected region, including assistance for treatment centers and monitoring programs.

The travel restrictions come amid growing global concern about the outbreak's potential to spread internationally through cross-border travel and trade.