WASHINGTON (Reuters) - US President Barack Obama on Friday revived the system of Guantanamo military trials for foreign terrorism suspects, angering supporters who said he had broken a promise to end the controversial tribunals set up by the Bush administration. Obama said the commissions would be restarted as an option for trying prisoners at the US military base in Cuba after undergoing several rule changes, including barring statements obtained using cruel interrogation methods and making it more difficult to use hearsay evidence. These reforms will begin to restore the commissions as a legitimate forum for prosecution, while bringing them in line with the rule of law, said Obama, who had opposed the Military Commissions Act enacted during the Bush administration. He (the president) is determined to reform the military commissions as an available form, along with the federal courts, for prosecution of detainees at Guantanamo, Pentagon spokesman Bryan Whitman told reporters. Rights groups, who have been long been critical of Washingtons treatment of foreign terrorism suspects, starting with the detention centre at Guantanamo, rejected the notion that the tribunals could be reformed. Amnesty International accused Obama, who took office in January, of breaking a major campaign promise. The groups US researcher, Rob Freer, said, No amount of tinkering with their rules can fix this discredited system. These military commissions are inherently illegitimate, unconstitutional and incapable of delivering outcomes that we can trust. Tweaking the rules of these failed tribunals so that they provide 'more due process is absurd, said Anthony Romero of the US Civil Liberties Union. The administration asked on Friday for a 90-day delay in the court proceedings to allow time for the new rules to take effect. The rule changes must be shown to Congress 60 days before they go into force. The secretary of defence will be sending to Congress several changes to the rules for military commissions, Whitman said. The department believes that these rule changes will improve the process.