The leaders of the United States, Mexico, and Canada pledged to combat the spread of the H1N1 swine flu and address climate change at their summit, known as the "three amigos." However, they disagreed on trade issues. US President Barack Obama, Mexican President Felipe Calderon, and Canadian Prime Minister Stephen Harper met amid economic challenges in their countries, with a US recovery seen as crucial for regional progress. Obama and Harper promised to share information to prepare for a potential increase in the H1N1 virus in the upcoming months, while Calderon emphasized the need for all three countries to responsibly handle the situation and minimize its impact on their citizens. All three leaders pledged to uphold the North American Free Trade Agreement that connects their nations in trade, though they had differing views on certain issues. Harper brought up Canada's concerns with Obama about the "Buy American" provisions in the $787 billion U.S. economic stimulus plan, which Canadian companies fear could exclude them. Canada is the United States' biggest trading partner. Obama emphasized the importance of recognizing that no widespread protectionist measures have been implemented, and that the "Buy American" provisions only apply to the stimulus and do not jeopardize the billions of dollars in trade between the two countries. Calderon, who is seeking to persuade Obama to resolve a cross-border trucking dispute to allow Mexican trucks to enter the United States, stated that all three leaders agree on the necessity of adhering to NAFTA and addressing unresolved issues that hinder regional competitiveness. Obama informed Calderon that he was collaborating with the US Congress to address safety concerns related to Mexican trucks. He emphasized the importance of avoiding protectionism and expanding trade between the United States, Mexico, and Canada. The leaders also released a statement expressing their commitment to combatting climate change and preparing for the global summit in Copenhagen.