The decades-old dispute arose last week when former U.S. Ambassador to Canada Paul Cellucci told an Ottawa conference he agreed with Canada that the Northwest Passage was Canadian territory and not an international free passage as the United States contends.
"It is in the security interests of the United States that it be under the control of Canada," Cellucci said.
Within hours, the current U.S. ambassador, David Wilkins, issued a statement reiterating Washington's insistence the passage is international and open to all, The Washington Post reported Monday.
The passage is becoming more appealing to shipping interests as global warming is reducing the permanent ice, making the route more accessible and faster than sailing around the continent, the Post said.