Deposed Iraqi President Saddam Hussein has reportedly yielded no direct intelligence information since his capture near his home town of Tikrit.
The US said Saddam Hussein offered no resistance
He has "not been co-operative in terms of talking", a senior US official said, though the capture appears to have led to a number of further arrests.
US officials were also cautious about his eventual fate as calls came for him to be tried either in Iraq or abroad.
Two car bombs exploded in the Baghdad area on Monday, killing eight people.
US Defence Secretary Donald Rumsfeld said Saddam Hussein was being accorded the privileges of a prisoner-of-war under the Geneva Convention. But he said America was not defining him as a PoW.
Mr Rumsfeld said Saddam Hussein's fate would be decided at a senior level.
He warned that any trial would have to be "acceptable and appropriate and would ensure that he would be brought to justice".
Iraq's new US-backed leaders have been demanding a trial under an Iraqi tribunal formed last week.
The US military has said it has identified a militant cell in Baghdad and made a number of arrests of anti-coalition figures in the city on the basis of information "gleaned" from Saddam Hussein's capture.
A couple of key individuals had been seized in Baghdad since Saturday, said spokesman Brigadier General Mark Hertling.
These included a high-ranking former figure from the Saddam government who in turn "gave up a few others," he said.
General Hertling told AP news agency that the arrests had been prompted by the transcript of Saddam Hussein's initial interrogation as well as a briefcase of documents found in his hideout.
The spokesman added that he expected Saddam Hussein to produce "some significant intelligence over the next couple of days".
Time magazine, quoting a US intelligence official, reports that he denied during initial questioning that his country possessed weapons of mass destruction.
"The US dreamed them up itself to have a reason to go to war with us," the magazine quoted the former president as saying.
'I am the president of Iraq'
The whereabouts of the former president is unclear. Reports that he has been moved to a US facility in Qatar have been denied by the Iraqi authorities.
Colonel James Hickey, who led the raid on Saddam Hussein's hideout on Saturday, has revealed that soldiers were seconds away from throwing a hand grenade into the pit where he was hiding before he surrendered.
The operation was launched, Colonel Hickey said, on the basis of information from an individual arrested in Baghdad on Friday, then brought to Tikrit for interrogation on Saturday morning.
It is not known if the Americans intend to pay a $25m reward offered for information about him.
The troops who came across Saddam Hussein on Saturday were offered "negotiations", spokesman Major Brian Reed said on Monday.
"I am Saddam Hussein, I am the president of Iraq and I want to negotiate," the former leader was quoted as saying in English from his pit.
The soldiers, according to Major Reed, replied with the words "President Bush sends his regards".
Calls for trial
Iran has added its voice to calls for Saddam Hussein to be tried for crimes, saying he should be tried in an international court over the 1980-1988 Iran-Iraq war.
SADDAM: POSSIBLE CHARGES
Campaign against the Kurds in the 1980s, including the use of poison gas at Halabja
Suppression of Kurdish and Shia revolts after the first Gulf War
Brutality against the Marsh Arabs
Crimes committed during the wars against Iran and Kuwait
Possible involvement in recent attacks on coalition forces and other targets in Iraq
The US-appointed Iraqi Governing Council (IGC) has called for him to be tried inside Iraq by Iraqi judges "under the supervision of international experts".
The current president of the IGC, Abdel
Aziz al-Hakim, said Monday that Saddam Hussein could face the death penalty if convicted in an Iraqi court.
A special tribunal was set up in Iraq last week to try leading members of the former government.
Charles Heathley, spokesman for the US-led administration in Iraq, said on Monday he expected the new tribunal would charge Saddam Hussein "in due course" and ask the coalition to hand him over.
However, some human rights groups say an international tribunal - without the power to award the death penalty - would be preferable to a trial in Iraq.
The International Committee of the Red Cross (ICRC) has said it expects to have access to the captured former president .
There was no fixed time frame for the visit, a spokesman told AP.
"But we expect Saddam Hussein - as any other presumed, real or accepted PoW - will at some stage be visited by the ICRC."
World leaders have welcomed the capture, including some who opposed the war to oust Saddam Hussein such as President Jacques Chirac of France who said it would strongly contribute to democracy and stability in Iraq.
There was also condemnation of his treatment in some parts of the Arab world.
Abdel Azziz Rantissi, a leader of the Palestinian militant organisation Hamas, accused the US of an "ugly and despicable... insult to all Arabs and an insult to Muslims".