The man, whose name officials did not release, was removed from the plane at Pierre Elliott Trudeau International Airport and arrested, said Lauren Gaches, a spokeswoman for the Transportation Security Administration.
Other passengers on Aeromexico Flight 006 from Charles De Gaulle Airport to Mexico City International Airport were re-screened and allowed to re-board the flight, Gaches said.
As a matter of policy, the TSA does not confirm or deny whether a person appears on a government watch list.
"The United States' ability to refuse entry into its territory of any flight it deems to present a threat to its security is recognized by numerous countries and is consistent with international agreements," Gaches said.
Montreal airport official Marie-Claude Desgagnes said the plane was allowed to take off shortly after 10 p.m. EDT.
TSA referred questions to Aeromexico and Canadian authorities. In Mexico City, a woman who answered the phone at Aeromexico late Sunday said no one was available to talk to the news media. In Canada, a Royal Canadian Mounted Police official said officers assisted Canada Border Services but delined to provide further details.
