The leaders of the United States, Mexico, and Canada pledged to work together to combat the spread of the H1N1 swine flu and address climate change during their "three amigos" summit. However, they disagreed on trade disputes. US President Barack Obama, Mexican President Felipe Calderon, and Canadian Prime Minister Stephen Harper met amidst economic challenges in their countries, with a US recovery being crucial for regional progress. Obama and Harper announced plans to exchange information to prepare for a potential increase in H1N1 cases in the coming months. Calderon emphasized the importance of being ready for the virus's return and minimizing its impact on the population. All three leaders pledged to uphold the North American Free Trade Agreement that connects their nations through trade, although they had differing views on certain issues. Harper brought up Canada's concerns to Obama regarding the "Buy American" rules in the U.S. economic stimulus plan, which Canada worries could exclude Canadian businesses. Canada is the largest trading partner of the United States. Obama emphasized the importance of recognizing that no widespread protectionist measures have been enforced and that the "Buy American" rules only apply to the stimulus package and do not jeopardize the billions of dollars in trade between the two countries. Calderon, who is working to convince Obama to resolve a dispute over cross-border trucking to allow Mexican trucks into the U.S., stated that all three leaders agree on the importance 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 regarding 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 combating climate change and preparing for a global summit on the issue in Copenhagen in November.