The United States has said that the countries in South Asia should work more effectively together to help reduce the threat of terrorism to any one of them. Speaking in Washington, the US State Department spokesman P J Crowley said, the US have encouraged countries in the region, including Pakistan, Afghanistan and India to work, collectively together as they confront a shared threat, and some of these challenges can only be resolved through effective and coordinated action across the region. Crowley said, concerned over the extremist threat that exists within Pakistan's borders, the US have asked Islamabad to take decisive action against such elements operating from its soil. Responding to allegations by Afghan National Security Advisor Rangin Dadfar Spanta that Pakistan continues to mentor terrorist outfits, Crowley said one cannot look at this in isolation and through the lens of a zero-sum calculation. Crowley said the countries in South Asia should work more effectively together to help reduce the threat of terrorism to any one of them.