By MATTHEW DALYHONOLULU (AP) â¿¿ President Barack Obama signed a $633 billion defense bill for next year despite serious concerns about the limits Congress imposed on his handling of terror suspects and lawmakers' unwillingness to back the cost-saving retirement of aging ships and aircraft. Obama had threatened to veto the measure because of a number of concerns, but relented because he couldn't pick and choose specific sections. However, in a statement, the president spelled out his concerns about restrictions on his ability to carry out his constitutional duties as commander in chief. Specifically, he complained that the bill limits the military's authority to transfer third-country nationals being held at a detention facility in Parwan, Afghanistan. He also took issue with restrictions on his authority to transfer terror suspects from the U.S. military prison at Guantanamo Bay, Cuba. "Decisions regarding the disposition of detainees captured on foreign battlefields have traditionally been based upon the judgment of experienced military commanders and national security professionals without unwarranted interference by members of Congress," Obama wrote. He said the section of the bill related to detainees in Afghanistan "threatens to upend that tradition, and could interfere with my ability as commander in chief to make time-sensitive determinations about the appropriate disposition of detainees in an active area of hostilities." Obama promised when he took office four years ago to close the prison at Guantanamo, but congressional opposition from Republicans and some Democrats have prevented him from fulfilling that vow. The law limits his authority to transfer terror suspects to foreign countries or move them to the United States. Obama insisted that he still believes that Guantanamo should be shuttered because operating the facility "weakens our national security by wasting resources, damaging our relationships with key allies and strengthening our enemies." The president said his administration will interpret the bill's provisions and if they violate the constitutional separation of power, he will implement them in a way to avoid that conflict.