Two British ISIS militants charged for their alleged involvement in the torture and beheadings of four Americans, including photojournalist James Foley, are due to stand trial in the US.

Known by their captives as ‘the Beatles’ because of their British accents, El Shafee Elsheikh and Alexanda Kotey are being brought to a federal court to face a judge for the first time.

The men are in FBI custody being charged with terrorism offences related to hostage-taking and the killing of four US citizens, as well as citizens of the UK and Japan, said Assistant Attorney General for National Security John Demers.

“Today’s announcement is a reminder of the threat that we continue to face from radical Islamic terrorists,” Mr Demers said.

He called it a “good” but “solemn day”.

“These terrorists despise the freedoms and way of life we cherish as Americans and are hell-bent to impose their ideologies on a world that continues to reject them,” Mr Demers said.

Alexanda Amon Kotey, left, and El Shafee Elsheikh, who were allegedly among four British jihadis who made up a brutal Islamic State cell dubbed “The Beatles”. Photo: AAP

The men are said to have been responsible for executing 27 victims in a series of gruesome videos posted online, dating back to August 2014.

The four US citizens killed by the notorious Islamic State cell were James Foley, Steven Sotloff, Peter Kassig and Kayla Mueller. They were journalists and aid workers.

The families of the four Americans released a joint statement saying they can now “pursue accountability for these crimes against our children in a US court”.

“We are hopeful that the U.S. government will finally be able to send the important message that if you harm Americans, you will never escape justice,” the joint statement released by the Foley Foundation read.

“And when you are caught, you will face the full power of American law,” they continued.

A Kurdish security officer escorts Alexanda Kotey, left, and El Shafee Elsheikh, at a security center in Kobani, Syria. Photo: AAP

One of the cell’s tactics was to behead civilians after making them kneel on the ground dressed in orange jumpsuits.

Videos of the killings were distributed via social media.

The accused will make their initial appearance in a federal court in Alexandria, Virginia, later on Thursday (Australian time).

The two, who have been stripped of their British citizenship, were captured by US-backed Kurdish forces in Syria and were later transferred to holding cells in the Middle East.

As part of a deal with the UK, the US promised not seek the death penalty but the men could face life sentences.

The US made the pledge in order to obtain evidence held by British authorities.

The leader of the cell was killed in an air strike in Syria while a fourth member was captured in Turkey.

“Our message to other terrorists around the world is this: if you harm Americans, you will face American arms on the battlefield or American law in our courtrooms.” Attorney General Bill Barr said in a statement.

“Either way, you will be pursued to the ends of the earth until justice is done,” he continued.

-with AAP