Reports say that the United States has identified the masked Islamic State militant who murdered two kidnapped American journalists in separate videotaped beheadings.

FBI chief James Comey made this known to reporters at a briefing in Washington on Thursday, saying that,  “We believe we have identified the executioner…, I won’t tell you who it is.”

The British ambassador in Washington, Sir Peter Westmacott, had previously said that the allies were close to identifying the suspect.

Comey did not confirm or deny reports that the suspect in the killing is British, but said the FBI was concerned that another film from the Islamic State group features someone with a North American accent.

It features a masked militant in combat fatigues speaking in English.

 Comey said, “There’s no doubt that there’s someone speaking with a North American-accented English on that video, so that’s a big focus of ours right now.”