A US Army Honour Guard passed out in front of Barack Obama as the outgoing US President gave a farewell speech to the armed forces on Wednesday.

The soldier was pictured face down on the ground while other guards remained standing, as if nothing had happened to their colleague.

The serviceman is believed to have fainted as Mr Obama addressed the military at Joint Base Myer-Henderson Hall in Arlington Virginia, for the last time before he leaves office.

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It is unclear what happened to the guard, but it is not uncommon for soldiers to pass out during ceremonies because they often have to stand to attention for hours at a time.

Moments earlier Mr Obama had told members of the US military that there is “no greater privilege and no greater honor” than serving as their Commander-in-Chief.

He said: “As I reflect on the challenges we have faced together and on those to come, I believe that one of the greatest tasks before our armed forces is to retain the high confidence that the American people rightly place in you.

Fainting is not uncommon for Honour Guards, who have to stand for hours at a time (AFP/Getty Images)

“We must never hesitate to act when necessary to defend our nation, but we must also never rush into war because sending you into harm's way should be a last and not first resort.”

Army Photographic Competition 2016 Show all 13 1 /13 Army Photographic Competition 2016 Army Photographic Competition 2016 Corporal Sean Neill, from Kilmarnock, kissing his daughter Madison in the streets of Glasgow after the 400 strong Homecoming Parade. The photo, by Mark Owens, has been named Winner of Best Online Image (voted by the public) in the Army Photographic Competition 2016 Mark Owens/Army HQ Scotland/PA Wire Army Photographic Competition 2016 This photograph shows Officer Cadets from Royal Military Academy Sandhurst (RMAS) on Exercise Dynamic Victory, Grafenwoehr & Hohenfels Training area, Bavaria Bombardier Murray Kerr RA/PA Wire Army Photographic Competition 2016 Great Men, by Bombardier Murray Kerr RA Bombardier Murray Kerr RA/PA Wire Army Photographic Competition 2016 The photograph shows the changing room buzzing 30 minutes before forming up Sergeant Rupert Frere RLC/PA Wire Army Photographic Competition 2016 Prepping for the Worst, by Cpl Timothy Jones Cpl Timothy Jones/PA Wire Army Photographic Competition 2016 Y Company, 1st Battalion The Royal Regiment of Fusiliers, conducting jungle warfare training in Brunei, learning to live, survive and fight in the unique training environment Cpl Timothy Jones/PA Wire Army Photographic Competition 2016 Right Hook, by Bombardier Murray Kerr RA Bdr Murray Kenneth Kerr, Royal Artillery/PA Wire Army Photographic Competition 2016 Army Photographic Competition 2016 The Climb, by Capt Ben Norfield, RGR Capt Ben Norfield, RGR/PA Wire Army Photographic Competition 2016 This photograph shows the TIGERS Freefall Parachute Display Team from the 1st Battalion The Princess of Wales's Royal Regiment (1 PWRR) send a Birthday message to the Queen from 8,000 feet above Paderborn in Germany Dominic King AMC/PA Wire Army Photographic Competition 2016 Nightlife in Otterburn, by Cpl Timothy Jones Cpl Timothy Jones/PA Wire Army Photographic Competition 2016 The photograph shows Garrison Sergeant Major Andrew Stokes of the Coldstream Guards making inspections of the soldiers drill Sergeant Rupert Frere RLC/PA Wire Army Photographic Competition 2016 Y Company, 1st Battalion The Royal Regiment of Fusiliers, conducting jungle warfare training in Brunei, learning to live, survive and fight in the unique training environment Cpl Timothy Jones/PA Wire

He called for a smooth transition as he hands over control of the military to President-elect Donald Trump.