International Criminal Court (ICC) prosecutors have said a probe indicates members of the US armed forces and the CIA may have committed war crimes by torturing detainees in Afghanistan.
The prosecution office said US armed forces personnel "appear to have subjected at least 61 detained persons to torture" in Afghanistan, mainly in 2003 and 2004.
The report added that CIA operatives may have tortured at least 27 detainees in Afghanistan and elsewhere mainly in the same time period.
Prosecutors said they will decide "imminently" whether to seek authorisation to open a full-scale investigation in Afghanistan.
Established in 2002, the ICC is the world's first permanent court set up to prosecute war crimes, crimes against humanity and genocide.
More than 120 countries around the world are members, but superpowers including the United States, Russia and China have not signed up.
Former US president Bill Clinton signed the Rome treaty which established the court on December 31, 2000, but his successor in the White House, George W Bush, renounced the signature, citing fears that Americans would be unfairly prosecuted for political reasons.
Even though the US is not a member of the court, Americans could still face prosecution at its headquarters in The Hague if they commit crimes within its jurisdiction in a country that is a member, such as Afghanistan, and are not prosecuted at home.
So far, all of the ICC's trials have dealt with crimes committed in Africa.
Prosecutors say investigations also are reportedly under way in Poland, Romania and Lithuania - all signatories to the Rome treaty - into possible crimes at CIA detention facilities in those countries.
The abuse allegations came in a wide-ranging annual report into the prosecution office's so-called preliminary examinations, which involve studying reports of possible crimes to establish if they fall under the court's jurisdiction.
The same report said that Taliban and Afghan government forces may also have used torture and committed other atrocities in that country's long and bitter conflict.
Referring to the alleged US war crimes, the report said they "were not the abuses of a few isolated individuals. Rather, they appear to have been committed as part of approved interrogation techniques in an attempt to extract 'actionable intelligence' from detainees".
The report adds that: "The information available suggests that victims were deliberately subjected to physical and psychological violence, and that crimes were allegedly committed with particular cruelty and in a manner that debased the basic human dignity of the victims."
Before deciding to open a full-scale investigation, ICC prosecutors have to establish whether they have jurisdiction and whether the alleged crimes are being investigated and prosecuted in the countries involved.
The ICC is a court of last resort that takes on cases only when other countries are unable or unwilling to prosecute.
The report noted that US authorities have conducted dozens of investigations and court martial cases and says ICC prosecutors are seeking further clarifications on their scope before deciding whether any American cases would be admissible at the ICC.