President Barack Obama was on Friday set to meet families of the victims of the September 11 2001 attacks and the 2000 bombing of the USS Cole, a meeting due to highlight some of the difficulties his administration confronts in seeking to close the detention centre at Guantánamo Bay within a year.

Mr Obama marked a clear break with the Bush administration in his second day in office by signing executive orders to shutter Guantánamo and to rule out interrogation techniques he considers torture. But the practical problems those issues represent will take much longer to resolve.