President George W Bush was fully aware of and an "integral part" of the CIA's torture of terror suspects, his vice-president Dick Cheney said Wednesday.

The long-awaited US Senate report released Tuesday on the program of harsh treatment and torture of detainees said Bush only learned details of it in 2006, four years after it started in the wake of the 9/11 attacks on New York and Washington.

Detainees were beaten, waterboarded -- some of them dozens of times -- and humiliated through the painful use of medically unnecessary "rectal feeding" and "rectal rehydration", the report said.

Speaking to Fox News, Cheney denied Bush was kept out of the loop. He said the then-president "was in fact an integral part of the program and he had to approve it."

Asked if Bush knew specific details of how specific interrogations were being conducted, Cheney was more vague, saying: "We did discuss the techniques. There was no effort on our part to keep him from that."

Bush has yet to speak out publicly on the Senate report, which has drawn scathing criticism worldwide of what the CIA has called "enhanced interrogation techniques", amid and calls for those involved to face trial.

The CIA deliberately misled Congress and the White House about the value of the intelligence its interrogators were gathering, the report concluded.

But Cheney did not mince his words in rejecting that.

"The report's full of crap, excuse me. I said hooey yesterday -- let me use the real word," he thundered.

The investigation was "deeply flawed" and "didn't bother to interview key people involved in the program," he said.

According to the 500-page declassified summary of the Senate Intelligence Committee's findings, the first CIA briefing with Bush on the interrogation techniques was on April 8, 2006.

Some of the prisoners -- including Abu Zubaydah, allegedly Osama Bin Laden's right-hand man, and Abd al-Rahim al-Nashiri, who allegedly led Al-Qaeda operations in the Gulf -- were subjected to the torture starting in 2002, it said.

That US interrogators tortured Al-Qaeda suspects in secret jails was known. But the detailed Senate report into the scandal was seized upon by America's shocked friends and gloating enemies alike.

China and Iran, whose own human rights records have often been criticized by Washington, denounced the abuses -- but so did Germany and the new pro-US leader of Afghanistan.

"Such a gross violation of our liberal, democratic values must not happen again," German foreign minister Frank-Walter Steinmeier said, reflecting the embarrassment of Washington's European allies.

America's great power rival China -- often on the end of US censure for its rights record -- was equally unimpressed.

"We believe the US side should reflect upon itself, correct its ways and earnestly respect and abide by the rules of international conventions," Chinese foreign ministry spokesman Hong Lei said.

Sensing an opportunity to poke its traditional foe, Iran seized upon the report to throw back some of the human rights criticism that its own notorious prisons regularly receive.

Iran's supreme leader Ayatollah Ali Khamenei took to Twitter to declare the United States a "symbol of tyranny against humanity" -- not just in the CIA torture program but in domestic law enforcement.

The United Nations said the program violated international law and basic human rights, and British-based advocacy group CAGE demanded criminal proceedings.

Around the world, human rights bodies demanded that current US President Barack Obama -- who halted the torture but has not gone after the perpetrators -- take legal action.

That is unlikely. In Washington, a senior official told reporters that nothing in the Senate Intelligence Committee report would change a decision not to prosecute.

The report, released by Democratic committee chair Dianne Feinstein over the objections of some of her Republican colleagues, said CIA torture had been more brutal than previously acknowledged.

It was also badly supervised and ineffective, it found.

In response to the report, Obama acknowledged that torture had been counterproductive and contrary to American values.

"No nation is perfect," he said. "But one of the strengths that makes America exceptional is our willingness to openly confront our past, face our imperfections, make changes and do better."