WASHINGTON - Montana Sen. Conrad Burns said he "misspoke" when he claimed at a news conference this week that terrorists involved in the Sept. 11 attacks entered the United States from Canada.
But the Republican insisted Tuesday his mistake shouldn't obscure security problems "that clearly exist on the border."
Canadian ambassador Frank McKenna demanded a retraction from Burns on Monday after the senator said: "We've got to remember that the people who first hit us in 9-11 entered this country through Canada."
In a letter to McKenna, Burns noted a man who planned to bomb a New York City subway in 1997, Gazi Ibrahim Abu Mezer, was arrested on this third illegal entry into the United States from Canada.
He also noted Ahmed Ressam, the so-called Millennium Bomber who plotted an attack on the Los Angeles International Airport, entered illegally from Canada. His letter did not mention that Canadian police helped U.S. authorities catch Ressam before he could carry out his plans.
"These incidents are disturbing and should not be ignored," Burns wrote.
"We still have much work ahead of us … The threat of terrorists crossing from the United States to Canada is just as real and those who wish to do harm should not be able to cross a porous border to carry out an attack in either country."
McKenna has made it a priority to emphasize Canada's commitment to security and debunk the myth that the Sept. 11 terrorists crossed into the United States from the north.
"Let me assure you that Canada takes matters of domestic and continental security very seriously," he wrote to Burns.
"(We) share a wide-ranging security partnership on issues such as passports, borders, fighting terrorism, military co-operation overseas, Norad, visa-screening, drug-trafficking, people-smuggling and law-enforcement."
Last week, the House of Representatives passed a border security bill, primarily aimed at Mexico, that included a new initiative to study building a security wall along the Canada-U.S. border.
Canadian officials said they had no interest in the plan and it had never been raised with them in security meetings with their U.S. counterparts.