The two men are thought to be members of the ISIS-affiliated group

Two Londoners alleged to be members of the ISIS-affiliated “Beatles” group may face trial in the US as early as this summer, British media reported.

Alexanda Kotey and El Shafee Elsheikh, who are currently being held by western-backed Kurdish forces in the north of Syria, are expected to soon be transferred to US custody.

As US President Donald Trump prepares to withdraw American troops from Syria, there are growing concerns that the men could be broken out of jail by ISIS supporters or set free by their overstretched captors.

The men, who have been stripped of their British citizenship, are deemed to be members of a four-member execution cell led by a fighter dubbed "Jihadi John", identified as Mohammed Emwazi.

Among the 27 beheaded western hostages who fell victim to the group were US journalists James Foley and Steven Sotloff and British aid workers David Haines and Alan Henning.

Mr Kotey and Mr Elsheikh were captured by the Syrian Democratic Forces in January last year. FBI agents were given permission the following month to visit Britain to review evidence against the men on an "information-sharing basis only".

Britain wants the US to prosecute the men because it maintains there would be "insufficient evidence" to do so in the UK.

In October 2015, however, it asked for an assurance that the evidence it provided would not be used to seek the death penalty against the suspects.

Britain abolished the death penalty more than 50 years ago and has since upheld an anti-death penalty stance.