Prime Minister Stephen Harper praised the North American Free Trade Agreement on Tuesday after a two-day summit, but also raised concerns about the "thickening" of the border with the United States.

Prime Minister Stephen Harper speaks to reporters on Tuesday after a two-day summit with North American leaders in New Orleans.
(CBC)

The prime minister made the comments at a joint press conference with U.S. President George W. Bush and Mexican President Felipe Calderon at the end of the so-called Three Amigos summit in New Orleans.

He said the business communities of both Canada and the U.S. have voiced alarm over how more extensive border security screenings and congestion could impede the movement of people and goods.

While free trade was not on the summit's formal agenda, the topic came up in discussions because the two Democratic candidates vying to replace the U.S. president in the November election have suggested NAFTA could be renegotiated.

"We'll be prepared for any eventuality," Harper said. "My preference is not to renegotiate what we discussed in the past, and to talk about the future."

Despite public statements by Senators Barack Obama and Hillary Clinton on NAFTA, Harper said he believes whoever next occupies the White House will realize the 15-year-old agreement's benefits and seek to build upon it to ensure the borders flow more freely.

"We've had an extremely productive relationship with the current administration, and I anticipate that Canada will have a productive relationship with the next administration," he said.

Harper, in turn, also emphasized numerous times during the press conference that Canada is the biggest and most stable energy supplier to the U.S. in the world.

"That is of critical importance to the United States," he said. "And if we had to look at this kind of an option, I think quite frankly, you know, we would be in an even stronger position now than we were 20 years ago. And we'll be in a stronger position in the future."

'Special emphasis' on Detroit-Windsor crossing

Bush, replying to criticism from Obama and Clinton, praised NAFTA as a "good, comprehensive agreement" that has benefited all three nations.

"Now is not the time to renegotiate NAFTA or walk away from NAFTA," Bush said. "This agreement has been beneficial for creating wealth in our neighbourhood."

The three leaders said the talks focused on border security, trade and a joint combatting organized crime.

Harper also said "special emphasis" would be given on the Detroit-Windsor crossing, but did not give specific details.

U.S. officials have hinted at a possible announcement about improving the border crossing, a four-lane bridge built in 1929 that handles one-quarter of all Canada-U.S. trade.

But ahead of the meeting, Canadian business leaders said they were looking for reassurance that the trilateral trade agreement would be here to stay.

Tom d'Aquino, president of the Canadian Council of Chief Executives who is also attending the summit, said border delays are a large worry for Canada's business community.

"Perhaps it means some deterred investment, and we're deeply concerned about that," he said.

After breakfast, the three leaders met privately with the North American Competitiveness Council — 30 private-sector representatives, or 10 from each country, who make recommendations on issues ranging from border security to trade.

The leaders' meeting with the business representatives is at the core of what anti-globalization protesters say is wrong about the summit, CBC's Keith Boag reported from New Orleans. 

"It takes place in secret … and it addresses only the agenda, in their view, of the corporate interests," Boag said. "It doesn't address the agenda of civil society."

Members of Harper's cabinet, including Public Safety Minister Stockwell Day and Industry Minister Jim Prentice, participated in the talks.

With files from the Canadian Press