Prime minister-designate Stephen Harper took aim at the American ambassador's criticism of the Conservatives' Arctic sovereignty plan on Thursday, in the party leader's first news conference since winning a minority government.

"The United States defends its sovereignty and the Canadian government will defend our sovereignty," Harper told reporters in Ottawa. "It is the Canadian people we get our mandate from, not the ambassador of the United States."

A day earlier, David Wilkins, the U.S. ambassador to Canada, said his government opposes Harper's proposed plan to deploy military icebreakers in the Arctic to detect interlopers and assert Canadian sovereignty over those waters.

Prime minister-designate Stephen Harper, Thursday.

"There's no reason to create a problem that doesn't exist," Wilkins said as he took part in a forum at the University of Western Ontario in London.

"We don't recognize Canada's claims to those waters... Most other countries do not recognize their claim."

During the federal election campaign, which culminated in Harper's win earlier this week, the Conservatives promised to spend $5.3 billion over five years to defend northern waters against the Americans, Russians and Danes.

U.S. Ambassador David Wilkins. (CP file photo)

"Sovereignty is something, you use it or you lose it," Harper said at the pre-Christmas announcement in Winnipeg.

• FROM DEC. 22, 2005: Tories plan to bolster Arctic defence

His plan included the construction and deployment of three new armed heavy icebreaking ships, as well as the eventual construction of a $2-billion deepwater port in Iqaluit and an underwater network of "listening posts."

At the time, Harper wouldn't say whether he would order military action if the ships or port detected an unauthorized submarine in Arctic waters.

Wilkins said he doesn't think that kind of military buildup is necessary in the Far North.

"We are simply having a disagreement on this," he said on Wednesday. "We have agreed to disagree, and there's no reason ... to say, 'There's a problem that's occurring and we gotta do something about it.'"

Wilkins also said he expects less anti-American sentiment from Harper's minority government, and added that he called Harper to offer congratulations on his election victory.

Also on Thursday, Harper acknowledged he had "a very friendly conversation" with U.S. President George W. Bush a day earlier, and hoped to arrange a meeting as soon as the leaders' schedules permit.