Tom Ridge was appointed after the 9/11 attacks on the US
America's first homeland security secretary has accepted some criticisms of the US "war on terror" made in a recent report by legal experts.
Tom Ridge told the BBC that the report's attacks on extended detention and torture were justified.
But he also said the US had been dealing with a new kind of threat.
The report the International Commission of Jurists said anti-terror measures worldwide had seriously undermined international human rights law.
After a three-year global study, the ICJ said many states had used the public's fear of terrorism to introduce measures including detention without trial, illegal disappearance and torture.
It said the framework of international law that existed before the 9/11 attacks was robust and effective, but had been actively undermined by the US and the UK.
Mr Ridge, who was appointed to the new post of homeland security secretary after the 11 September, 2001 attacks on the US, said the ICJ was on "solid ground" in its commentary "with regard to torture and sustained detention without due process".
In an interview with the BBC's World Today programme he said that regardless of what terrorism suspects had done, the US still needed "to afford them some sense of due process."
"It has taken a while for us to get to that point but we are certainly there now," he said.
He added that there was now a consensus in the US and beyond that water-boarding - a harsh interrogation technique that simulates drowning - was torture, saying there had been no allegations of its use since 2003.
'Dealing with it'
However, Mr Ridge also defended US policy, saying counter-terrorism work was now about detaining people before they were able to commit terrorist acts.
"The criminal justice system is about prosecution and counter-terrorism is about prevention," he said.
"When you are taking upon [yourself] the responsibility to prevent acts I think you do need to engage in slightly different tactics in order to ensure that it happens."
Mr Ridge said the US and other countries had had to deal with a new kind of enemy - "individuals who sought to kill innocent civilians, accepted a belief system that the end justified the means."
Many suspects had "embraced an ideology, a belief system, that said it's perfectly all right in order to advance a cause to kill innocents along the way", he said.
"They had no loyalty to a country so they're not the traditional prisoner of war, they don't wear the uniform of a country so we can't treat them as we have done in previous wars."
Mr Ridge added: "How we dealt with them in terms of returning them to their potential country of origin was a difficult issue that not only the United States but other countries have had to deal with.
"So, we're in the process of dealing with it."