Cuba: Classified US military documents released by WikiLeaks that give intelligence assessments of Guantanamo prisoners will not affect any of their cases, Attorney-General Eric Holder said on Tuesday.

"I certainly deplore the leaks," Holder told reporters after news organisations on Sunday disclosed details from the documents on nearly all of the terrorism suspects who have been held at the US military prison at Guantanamo Bay in Cuba.

Holder said releasing the documents was harmful in a number of ways, including hurting US relations with some US allies. But he said he does not see any impact on the cases to be tried.

Holder announced earlier this month that the self-professed mastermind of the September 11, 2001, attacks, Khalid Shaikh Mohammad, and four co-conspirators would be tried in a military tribunal at Guantanamo, where they are being held.

He said Congress made it impossible to try the suspects in a regular US court in New York, as Holder had wanted.