Prime Minister Stephen Harper praised outgoing U.S. President George Bush on Monday after arriving in New Orleans for the so-called "Three Amigos Summit."

The North American Leaders' Summit is the fourth such meeting between North America's most prominent leaders, where issues including trade, border, and energy will be discussed.

"What I appreciate most, what I've appreciated in our relationship over the past couple of years, is the fact that whether we agree or disagree, we're always able to talk very frankly, very upfront," Harper told Bush at a photo opportunity after an hour-long meeting with the U.S. president.

"The president has never promised me anything he couldn't deliver and that's always appreciated.''

Bush then thanked the prime minister for his "strong and effective leadership" at a NATO summit earlier this month in Bucharest. He also reaffirmed his support of the North American Free Trade Agreement, which has come under fire from Democratic nominees Barack Obama and Hillary Clinton, who have said they would like to renegotiate the deal.

CTV's Ottawa Bureau Chief Robert Fife, reporting from New Orleans, said it's expected that Bush, Harper and Mexican President Felipe Calderon "will reaffirm their commitment to the North American free trade deal" at a news conference on Tuesday.

But other than re-stating their commitment to the 14-year-old trade agreement, no substantive progress is expected to be made at this meeting, which has tended to be less about major agreements and more about cutting red tape.

"In terms of substance, I don't think you're going to get a lot of it," said Fife.

"(That's) largely because this is (Bush's) last summit and all eyes are looking at who will replace him," he told CTV Newsnet Monday afternoon.

New Orleans Mayor Ray Nagin and Michael Wilson, Canada's Ambassador to the U.S., were on hand at the airport Monday to greet Harper upon his arrival, as were schoolchildren and a jazz band.

Bush said he chose New Orleans to send a message about the city, parts of which were destroyed by flooding in the aftermath of Hurricane Katrina in 2005.

"I chose New Orleans for our meetings with Mexico and Canada because I wanted to send a clear signal to the people of my country that New Orleans is open for business,'' Bush said. "It's a good place to visit and after the devastation of Katrina, it's become a hopeful city."

The prime minister is likely to be questioned by reporters about Brenda Martin, a Trenton, Ont., woman who has been imprisoned in Mexico for over two years, and a recent raid on Conservative headquarters in Ottawa at the request of Elections Canada.

Harper spoke to Calderon about the Martin case Monday, Fife reported, but Calderon said he could not interfere with his country's justice system.

Fife had noted earlier that a Mexican judge is expected to rule in Martin's case on Tuesday.

Meanwhile, the outgoing U.S. leader is expected to use the summit to try expanding trade relations with his two neighbours -- they already boast the largest trading partnership in the world, worth almost $1 trillion annually.

The focus of much of the media coverage is likely to be on protests surrounding the meetings. Another major issue is border security -- something that threatens to overshadow Canadian concerns, Fife said.

"The big problem here is so much attention is always on the Mexican border and illegal immigration. But Canada gets kind of shuffled aside and it's not a big deal with us," he said, adding that many observers think bilateral meetings between Canada and the U.S. are more productive than the trilateral gatherings.