Prime Minister Stephen Harper emerged from a meeting with U.S. President Barack Obama and Mexican President Felipe Calderon Monday without learning whether Canada will be asked to join the Trans-Pacific Partnership, the new group pursuing free trade among its member nations.

Harper, Obama and Calderon -- the so-called 'three amigos' -- gathered at the White House for discussions that began at 11:15 a.m. local time, and lasted about two hours.

Both Mexico and Canada hope to join the Trans-Pacific Partnership (TPP), but Obama told reporters outside the White House that discussions about adding new members are "ongoing."

The nine member countries, including the United States, Australia, Vietnam, Singapore and Chile, are pursuing a tariff-free zone that would affect about 500 million consumers. However, Canada's supply management system, which governs dairy and egg products, is seen as a barrier to Canada's membership in the group.

Obama said every country, including Canada, would be expected to make changes to some of their practices when joining a multi-nation trade group. Without mentioning supply management specifically, Obama said there are issues the group would like Canada to address, but said that is "not unique."

"Every country that's participating is going to have to make some modifications," Obama said. "That's inherent in the process, because each of our countries have our own idiosyncrasies, certain industries that in the past have been protected."

Harper said Canada's desire to enter the trade partnership is part of an overall plan to broaden the country's free trade relationships around the world.

He did not address the supply management issue. However, he said officials "will attempt to promote and to defend Canada's interests, not just across the economy but in individual sectors as well."

CTV's Ottawa Bureau Chief Robert Fife said Monday that the day's talks left the Canadian contingent that was present unhappy.

"Canada was pushing very hard to be part of (the TPP), so was Mexico," Fife reported from Washington. "The president was holding out on that and there was a lot of disappointment."

Fife said if Canada is willing to enter negotiations to join the group, then it is also willing to negotiate issues such as its supply management mechanisms. But officials are frustrated that "the Americans are not letting us at the table."

"I think (the Americans) see that this very important trade pact will benefit their country a lot," Fife said. "By letting Canada in they may have to face some stiffer competition."

After the meeting, Harper appeared at The Woodrow Wilson Center, where he made clear his disappointment with Obama on another issue, the decision to delay the Keystone XL Pipeline project.

"The very fact that a ‘No' could even be said underscores to our country that we must diversify our energy export markets," Harper said.

Obama shelved the project under increasing pressure from environmental advocates and landowners concerned about the pipeline's route through the environmentally sensitive Nebraska Sandhills.

Obama put the project on hold pending further reviews, effectively stalling it until after the 2012 presidential election.

As a result, Canada has begun looking for other opportunities to export Canadian oil, with China among the likely target markets. It has also led to a move by the Conservative government to introduce legislation that would fast track projects, such as the Northern Gateway Pipeline, which would move oil from Alberta to B.C. for shipment to Asian markets.

The Conservatives' Budget 2012, released Thursday, outlines a "one project, one review" system that would drastically reduce the red tape and approvals needed for projects such as the Northern Gateway to go forward.

Canada has the world's third-largest oil reserves after Saudi Arabia and Venezuela, and the nation's daily output of 1.5 million barrels is expected to rise to 3.7 million by 2025.

Harper said the Keystone project has the potential to create tens of thousands of jobs on both sides of the border, and said "it's not possible" for the U.S. to get a friendlier or more secure supply of oil. He also downplayed the environmental impact of oilsands development, saying that while there are "environmental challenges," they are not outside the norm of other oil extraction projects.

But Harper also acknowledged that hydrocarbon energy sources will one day not be able to keep up with demand, which will make for a more diverse energy market in the future.

"The way I see the energy of the future, we're going to have lots of hydrocarbon still in the mix, including increased natural gas," Harper said.

‘Three Amigos Summit' achieves little

Meanwhile, Obama said after the meeting that the three men discussed measures to create jobs, ease barriers to trade and combat the drug cartels that wreak havoc in Mexico and beyond. But little of his announcement contained new measures or deals.

Obama told reporters that Harper led a discussion on making the borders between the three countries more efficient and secure, "so it is faster and cheaper to travel and trade."

He also hailed the ongoing plan for regulatory reform, which calls for the three nations to engage in meetings designed to simplify or eliminate regulations that stifle trade and job creation.

Obama said the men also discussed security issues, specifically how to combat gangs and drug traffickers that "pose a threat to our nations."

The meeting at the White House was meant to make up for a planned meeting last November at the Asia-Pacific summit. Only Harper and Obama ended up attending, however, after Calderon's top deputy was killed in a helicopter crash.

Mexico's ongoing drug war was on the agenda during Monday's meeting.

In Mexico, an estimated 50,000 people have been killed in the drug war since 2006.

The three men announced a new working group of North American and Central American officials to better defend against transnational organized crime.

This year will see the formation of the Central America Integration System-North America Security Dialogue, to share information in the hopes of countering organized crime groups, mainly drug cartels that are wreaking havoc in Mexico, as well as in Central America.

Christopher Sands, a senior fellow at the Hudson Institute, a conservative think tank, said Monday that Mexico has tried to crack down on the drug cartels and create instability within their leadership.

But it remains to be seen whether Mexico's next president will maintain the tough approach after July's elections.

"Some people think the new president of Mexico will take a softer line or, perhaps as presidents often do with organized crime, say, ‘Keep your violence amongst yourselves and we will leave you space to operate,'" Sands told CTV News Channel in an interview from Washington.

"That would have a big effect on Canada and the United States, because it would make it easier for the drug cartels to move product into both of our countries."

One new measure announced Monday is the creation of the North American Plan for Animal and Pandemic Influenza (NAPAPI), which gives the three nations the tools through which to better co-ordinate their response to future health pandemics.