U.S. agents began working at Paris’ Charles de Gaulle International Airport Sept. 3 to identify high-risk travelers before they board flights to the U.S.

The agents work for U.S. Customs and Border Protection, an agency of the U.S. Department of Homeland Security.

France joined seven other countries working in partnership with the agency’s Immigration Advisory Program.

The program allows U.S. personnel posted in foreign airports to make “no board” recommendations to carriers and host governments.

High-risk persons are identified through passenger analysis information or an assessment of passengers’ documentation.

According to a U.S. Customs and Border Protection news release, the program is to disrupt human trafficking, to combat the proliferation of fraudulent travel documents and to prevent improperly documented passengers from traveling to the U.S.

The policy also aims to avoid costs associated with removal proceedings, airline penalties and the transportation costs of taking an individual back to the originating airport.

The program has been implemented already in airports in Amsterdam, Netherlands; Frankfurt, Germany; London; Madrid, Spain; Tokyo; Seoul, South Korea and Warsaw, Poland.