An Air France flight bound for Detroit was diverted to Montreal on Wednesday after it was denied permission to land in the United States because a passenger was from the Democratic Republic of Congo, where an Ebola outbreak is underway.

Flight 378, which took off from Paris, was diverted after the Congolese national “was denied entry into the United States,” the airline said in a statement on Thursday.

“There was no medical emergency on board,” it added.

The Trump administration on Monday closed U.S. borders to anyone who had recently been in the Democratic Republic of Congo, Uganda or South Sudan, citing the Ebola outbreak.

The State Department has “strongly” urged Americans not to travel to those three countries. It also announced on Thursday that all U.S.-bound passengers — including American citizens and permanent residents — who were in those countries within 21 days of their arrival in the United States must only enter through Washington Dulles International Airport for enhanced screening.

U.S. Customs and Border Protection confirmed that it had prohibited the Air France flight from landing in Detroit. “Air France boarded a passenger from the Democratic Republic of Congo in error on a flight to the United States,” it said in a statement. “Due to entry restrictions put in place to reduce the risk of the Ebola virus, the passenger should not have boarded the plane.”

The agency did not immediately respond to a question about the passenger’s travel history.

The World Health Organization declared the Ebola outbreak a “public health emergency of international concern” on Sunday. It is suspected to have caused more than 130 deaths and nearly 600 infections, but there is little risk of it developing into a global pandemic, the W.H.O.’s director general said on Wednesday.

The entry restrictions imposed by the Trump administration on Monday do not apply to American citizens or U.S. service members. The restrictions are to be in effect for 30 days, at which point the administration could decide to extend them.