The captives have been dubbed "The Beatles" for their British accents.

NBC said among those being considered for transfer are Alexanda Amon Kotey and El Shafee el-Sheikh, two survivors of a four-man IS unit that saw kidnapped foreign journalists and others tortured

The prison could be used to jail indefinitely a number of "high-value" IS foreign fighters captured in Iraq and Syria, while sending less important detainees whose governments won't accept them to an Iraqi-run prison, NBC said, citing unnamed US officials and European diplomats.

The Trump administration is considering sending some captured Islamic State fighters, including the two "Beatles," British citizens who took part in beheadings, to the military-run prison in Guantanamo, Cuba, NBC reported Thursday.

Moving newly captured jihadists to Guantanamo would mark a shift in US policy by the Trump administration: after having peaked at 780 detainees, the facility has not received a new prisoner since 2008.

Most detainees have been released, and the current population is 40, including several key Al-Qaeda figures accused of plotting the September 11, 2001 and other attacks.

Their trials under the military justice system have stalled for more than a decade, and adding newcomers will raise concerns the Trump administration has little intention to respect their legal rights.

The US military recently repatriated two US citizens detained in Syria, and has sent their cases to civilian courts where they now face trial for supporting Islamic State.

A US military spokeswoman, Commander Sarah Higgins, had no comment about the NBC report and added: "there is no one identified for transfer to Guantanamo at this time."

"The detention facility at Guantanamo Bay is one disposition option for long-term detention of enemy combatants. Other options include transfer to foreign partners and prosecution in US courts."

Working with Britain

The cases of Kotey and Sheikh have been controversial in Britain.

According to unconfirmed reports, they were stripped of their British citizenship before they were captured in early 2018 in Syria, and the British government has made no effort to have them brought to Britain for trial.

British opponents of the death penalty have demanded that the US not be allowed to take control of them.

In July, Minister for Security Ben Wallace told parliament that the British government is "working closely with international partners to ensure that they face justice for any crimes they have committed."

At the same time, he said the British government's official position is that the Guantanamo prison "should close."

"Where we share evidence with

the US, it must be for the express purpose of progressing a criminal prosecution, and we have made that clear to the United States," he said.