The leaders of the United States, Mexico, and Canada, known as "the three amigos," are meeting in Mexico for a summit to discuss trade issues and the threat of drug gangs. President Barack Obama, Canadian Prime Minister Stephen Harper, and Mexican President Felipe Calderon will have dinner on Sunday night followed by talks on Monday. The main topics of discussion include boosting their economies, ensuring smooth trade, and addressing the issue of Mexican drug gangs operating across the US border and into Canada. While major agreements are not expected to be announced, Obama's national security adviser, Jim Jones, believes the summit will be a step towards future agreements. Calderon is likely to push Obama to resolve a cross-border trucking dispute. According to the North American Free Trade Agreement, Mexican trucks should be allowed to enter the United States, but American trucking companies argue that Mexican trucks are not safe. This issue has been ongoing for years. In response to the cancellation of a program allowing Mexican trucks to operate beyond the U.S. border zone, Mexico imposed $2.4 billion in tariffs on US goods in March. US business groups have been urging the White House to resolve the dispute, as they believe the ban could result in the loss of thousands of American jobs. Mexico's ambassador to the United States, Arturo Sarukhan, has expressed a desire for a final resolution to the trucking issue. He mentioned that he hoped to reach an agreement by the end of the year. Michael Froman, a top official at the White House, informed reporters that the Obama administration is very focused on the issue and is collaborating with the US Congress to address safety concerns. Canadian officials are concerned about the "Buy American" aspects of a $787 billion economic stimulus bill, as they worry it could exclude Canadian companies from US construction contracts funded by the stimulus. Canada is the US's biggest trading partner. Froman stated that the Obama administration is in discussions with Canada and other countries to find a way to implement the "Buy American" provision that is in line with the law and international obligations, while also minimizing disruptions to trade. Obama addressed concerns about potentially reopening the NAFTA treaty, stating that given the current weakened economies of the three nations involved, now is not the time to add enforceable labor and environmental protections as some in his party would prefer. He acknowledged the difficult economic situation but expressed interest in improving the treaty. Another important issue at the summit is addressing the escalating violence caused by Mexican drug gangs, despite Mexican President Calderon's efforts to combat them. Obama is supporting Calderon's actions, stating that he is pursuing the right course with great bravery. Obama assured Calderon of complete support during a visit earlier in the year, but Mexico is concerned about delays in receiving anti-drug equipment and training. Both leaders are expected to discuss the H1N1 swine flu outbreak and address climate change together as they prepare for upcoming international discussions in Copenhagen.