As the "Three Amigos" wrapped up a series of meetings in Mexico, U.S. President Barack Obama said his country is not harming trade with Canada through protectionist measures.

"I want to assure you that your prime minister raises this every time we see each other," he said Sunday at a press conference.

"(Prime Minister Stephen Harper) is expressing his country's concerns. ... I think it's also important to keep it in perspective: We have not seen some sweeping steps towards protectionism."

The Obama administration's "Buy American" provision, included in the US$787-billion stimulus package, limits foreign companies from partaking in U.S. construction projects.

Obama said that while the provision is legal, he was uncomfortable with it. However, he decided to pass the bill to get stimulus money flowing.

He said that for future contracts, individual U.S. states could loosen up such restrictions to "expand the trading relationship" with Canada.

"But I do think it's important to keep this in perspective: This in no way has endangered the billions of dollars of trade taking place between our two countries," he said.

Along with trade, the leaders of North America's three biggest countries on the continent talked about climate change and the ongoing drug war in Mexico.

The so-called "Three Amigos" meetings took place at an art museum in Guadalajara, Mexico's second-largest city, between Sunday evening and Monday afternoon.

On Monday afternoon, Harper, Obama and Mexican President Felipe Calderon held a news conference to discuss the outcomes of the North American Leaders' Summit.

The leaders acknowledged that the continent remains in a state of economic recovery and that they face many joint challenges, including the threat of a resurgent swine flu and problems with organized crime -- particularly in Mexico, where an ongoing drug war claimed an estimated 6,000 lives last year alone.

The leaders say they will continue to co-operate on the H1N1 threat, sharing resources and co-ordinating efforts to limit and monitor the swine flu's spread.

"We will continue to do everything we can to ensure that our people have timely and accurate information, and that our citizens are as prepared as they can be," the leaders said in the joint statement released to media.

The intention, they said, was to have a "joint, responsible and transparent" response to the evolving flu threat.

Additionally, the leaders acknowledged that the North American economy remains fragile, and that three countries must work to keep their trading relationship in a position where prosperity is "shared and sustainable."

Speaking about the economy at the news conference in Guadalajara, Obama said the economic crisis had taken away jobs "from Toronto to Toledo to Tijuana."

In a broader sense, Harper said that three countries were both "independent and interdependent," and that they faced many common problems.

On the subject of organized crime, Harper recognized Mexico for its "courageous" efforts in fighting its drug cartels. On the same note, Obama said the U.S. would offer Mexico the support it needs in its fight against the cartels.

In the joint statement, the leaders agreed that "transnational criminal networks threaten all three of our countries," and that those criminal groups have a reach that even extends outside North America. As a result, they will strive to work more closely with countries in Central America and the Caribbean in order to further improve safety and security.

At the news conference in Guadalajara, Obama and Harper thanked Calderon and his country for their hospitality during summit.

The Three Amigos summit was started in 2005 when former U.S. president George W. Bush first held the event near his Texas ranch.

The next one will take place in Canada in 2010, the same year that the G8 conference will be held in Ontario.

With files from The Associated Press