Amnesty International has said that prisoners held by the US in Iraq, Afghanistan and Guantanamo Bay have had fundamental human rights undermined.
Thousands have been jailed by the US since 11 September 2001
In a strongly worded report, released on Wednesday, the organisation accuses the US of tolerating prisoner abuse.
Images of US servicemen abusing Iraqis in Baghdad's Abu Ghraib prison would haunt the world for years to come, the report claims.
The report is published six days before the US presidential election.
Launching the report, "Human dignity denied: Torture and accountability in the War on Terror," Amnesty International officials called on the US government to condemn the use of torture and ban it through legislation.
US military reviews of prisoner abuse scandals cleared senior civilian and military officials of complicity or involvement.
Several US servicemen are currently facing courts martial for their alleged roles in the abuse at Abu Ghraib prison.
The Amnesty International report calls for an independent review of prison of alleged abuses of prisoners at Abu Ghraib as well as in Afghanistan and Camp X-Ray, the prison camp erected on the US military base at Guantanamo Bay, Cuba.
And the US was urged to ensure fair access to detainees, abolish secret detentions, ratify international treaties and pay reparations to victims of abuse.
When alleged abuse involved US agents, its response was denial and disregard for the Amnesty International's concerns
Amnesty report into the US military prison regime
"There remains a need for a full commission of inquiry that takes a genuinely
comprehensive and independent look at the USA's 'war on terror' detention and interrogation policies and procedures, and examines the activities of all government
agencies and all levels of government," the report said.
"Full accountability is crucial".
The US was also accused of falling short of maintaining in its own prisons the high standards of human rights that it demands of other nations.
"When it suited the US government's aims in its build-up to the invasion of Iraq, the administration cited Amnesty International's reports on torture in that country.
"When the alleged abuse involved US agents, its response was denial and disregard for the organisation's concerns," the report said.
Images of hooded and chained prisoners caused an outcry
The BBC's David Bamford says the report has very few moderate words for US President George W Bush.
But our correspondent notes that there may be little impact on the upcoming US vote, as much of the report's contents have been in the public domain for months.
Amnesty International spokeswoman Theresa Richardson said the timing of the report was not an attempt to influence the US campaign, but said the organisation was disappointed the issue had not been more prominently debated.
"We feel this is the last chance to get it on the agenda of the candidates," she said.