OTTAWA — Canada represents the greatest threat from terrorists trying to enter the United States, a top U.S. border agent told congressional lawmakers this week.

"As far as I am aware, all recent threat assessments have pointed to the northern border as the most likely point of entry into our country for terrorists," Brandon Judd, president of the National Border Patrol Council, told a House of Representatives' subcommittee on national security.

Judd, who represents more than 17,000 unionized Border Patrol agents, offered no specifics in his prepared statement to the committee, hearing testimony about reforming the agents' pay system.

Still, he warned the panel that U.S. officials must not become complacent about the dangers that lurk along the border with Canada and "the ongoing threat … to the safety of the American public."

"In the early to mid-1990s, San Diego and El Paso were ground zero for both illegal immigration and drug smuggling," he said. "In response, the border patrol threw all of its resources at those two areas without also strengthening the other areas of the border."

The thinking was that Arizona's inhospitable climate and terrain would help deter other illegal traffic from Mexico. The presumption proved wrong. But Judd said the same misguided thinking now threatens U.S. security along its northern front.