Obama, Mexico's Calderon vow more drug crime cooperation WASHINGTON (Reuters) - Mexican President Felipe Calderon told President Barack Obama on Monday that drug violence would continue unabated in his country unless the flow of American guns is curbed, while Obama promised closer cooperation with Mexico in fighting the narcotics trade. Obama acknowledged a responsibility to quell the U.S. demand for illegal drugs that helps drive narcotics trafficking, and said coordination with Mexico in the fight is becoming better than ever. "We have a responsibility to make sure not only guns but also bulk cash isn't flowing into Mexico, and obviously President Calderon takes very seriously his responsibilities to apply effective law enforcement within Mexico," Obama added. For his part, Calderon acknowledged the political reality that it is unlikely that American gun laws will be tightened amid in the run-up to the November 6 U.S. election in which Obama is seeking a second term in office. "I understand the internal problems from the political point of view," Calderon told a White House news conference with Obama and Canadian Prime Minister Stephen Harper, also referring to the right to bear arms enshrined in the U.S. Constitution. "But I know that if we don't stop the traffic of weapons into Mexico ... then we are never going to be able to stop the violence in Mexico," he said, noting there were around 8,000 gun stores along the U.S.-Mexican border. Mexico wants the United States to do more to reduce the use of illegal drugs by Americans and curb illegal arms shipments as well as cash flow to Mexican gangs. Turf wars between Mexican drug gangs have spread beyond smuggling hot spots along the U.S. border and increasingly brutal violence has sapped confidence in the country's security forces, harming its international standing. The drug-related violence also threatens Mexico's vital tourist industry. Obama said, "Defense ministers from our three countries (Mexico, the United States and Canada) met last week as a group for the first time ever, and we're going to be coordinating our efforts more closely than ever" to combat narcotics trafficking. Brutal clashes between drug cartels and Mexican authorities have killed more than 50,000 people since Calderon launched a crackdown on the cartels in late 2006. In a pitch for his country as a tourist destination, Calderon said the murder rate in the U.S. capital Washington remains higher than in big Mexican cities, a claim uttered while standing beside Obama in the White House Rose Garden. "That explains why, for instance, despite the perception of my country, last year 23 million tourists came to our country by plane, plus another 7 million in cruise ships, plus another 50 million who crossed the land borders," Calderon said. Drug gangs will be an important topic for the leaders at the Summit of the Americas in the Colombian resort town of Cartagena later this month. Obama said drug-trafficking poses a grave threat, especially to Central America. "If you start getting a larger and larger space in which they (drug gangs) have control over serious chunks of the economy, if they're undermining institutions in these countries, that will impact our capacity to do business in these countries," Obama said. Reporting By Alister Bull; Editing by Will Dunham