WASHINGTON — Frank McKenna, Canada's new ambassador to the U.S., has challenged the New York Times for saying in a recent editorial that terrorists often travel south across the Canadian border.

In an editorial last week, the newspaper called it "shocking" how little progress has been made in securing U.S. borders. "Suspected terrorists have long been entering the country from Canada," said the March 21 editorial.

McKenna took issue with the claim, which has been made in the past by other U.S. media organizations.

"In open societies such as ours, we all know that no security arrangement can be 100 per cent effective," McKenna wrote in a letter published by the Times on Saturday.

"But between Canada and the United States, the record is clear: our co-operation has reduced the threat of terrorism in both our countries."

McKenna noted the "smart border" action plan signed with U.S. officials just months after the terrorist attacks of Sept. 11, 2001, with Canada spending some $10 billion Cdn on security measures and a department similar to U.S. Homeland Security.

"Earlier this month, Michael Chertoff, the new secretary of Homeland Security, visited Canada and stated that together we are 'keeping terrorists out,' " wrote McKenna.

None of the Sept. 11 hijackers entered the U.S. through Canada, said McKenna.

Former Attorney General John Ashcroft also referred to the help of Canadian authorities in apprehending "millennium bomber" Ahmed Ressam in 1999, he added.