President Donald Trump has approved death by firing squad for convicted jihadist Nidal Malik Hasan, who shouted “Allahu Akbar” as he opened fire on American soldiers in 2009, killing 13 and injuring 32.

Sean Parnell, U.S. Assistant Secretary of War, on Monday said Mr Trump approved that Mr Hasan be executed by firing squad as recommended by Pete Hegseth, U.S. Secretary of War.

“Secretary of War Pete Hegseth has recommended—and President Donald J. Trump has approved—death by U.S. Army firing squad for convicted terrorist Nidal Malik Hasan, the jihadist who opened fire on unarmed American soldiers at Fort Hood in 2009,” Mr Parnell said.

Mr Hegseth will set the time and place of the execution.

Mr Hasan, a U.S-born Arab-American of Palestinian descent and former U.S. Army major, was convicted of mass murder after perpetrating the Fort Hood shooting on November 5, 2009.

Court-martialled in 2013, Mr Hasan was convicted of mass murder and has remained in detention on death row at the United States Disciplinary Barracks at Fort Leavenworth, Kansas, after losing every appeal to the Supreme Court.

Mr Hasan, who was 40 the year he carried out the attack, is now 56. Until 2009, when he carried out the shooting, Mr Hasan served as a psychiatrist in the Army Medical Corps.