President-elect Barack Obama's advisers are making plans to close the Guantanamo Bay prison and prosecute terror suspects in the United States, a plan that the Bush administration said Monday was easier said than done. Under the plan being drawn up by Obama's advisers, some detainees would be released and others would be charged in US courts, where they would receive constitutional rights and open trials. But, underscoring the difficult decisions Obama must make to fulfill his pledge of shutting down Guantanamo, the plan could require creation of a new legal system to handle the classified information inherent in some of the most sensitive cases. Many of the about 250 Guantanamo detainees are cleared for release, but the Bush administration has been unable to find a country willing to take them. Advisers participating directly in the planning spoke on condition of anonymity because the plans are not final.