The EU's home affairs commissioner Cecilia Malmstroem on Friday slammed Washington's failure to close the Guantanamo Bay detention centre as "a shame".
"We are very displeased, this is the opinion of the European Union and of the whole of Europe, of all the member states, expressed repeatedly in our contacts with the Americans," she said after launching new EU anti-terror measures two days before the 10th anniversary of the 9/11 attack.
"It is a shame that it is still open and that people have not been put on trial," she added.
"We continue to repeat to our American friends that it must be closed."
President Barack Obama signed a decree to close the camp after taking office in January 2009 but the move was blocked by Congress.