US President Donald Trump shared a video of himself with troops in Iraq, including a group that appears to be a Navy SEAL team.

Current and former defence officials said it was against usual policy to share their faces and location, and that the deployment of such elite forces is typically kept secret.

Reporters on the ground also heard one troop identify themselves to the president as the chaplain of SEAL team five.

"real names, faces, and identities, of personnel involved in special operations or activities, are usually a closely held secret in a combat zone," one former intelligence official told Newsweek.

US President Donald Trump tweeted a video that appeared to reveal the deployment of an elite Navy SEAL team in Iraq, potentially exposing their identities and locations.

The video, shared by Trump, the White House, and the press secretary, shows the president with service members wearing full battle gear and night vision goggles on their helmets.

It does not blur their faces, which current and former intelligence personnel told Newsweek was highly unusual and not in line with policy.

Here's the video, showing Trump posing with the troops:

According to a pool report from journalists on the ground, Trump took a picture with a special operations troop who said he was the chaplain for SEAL Team Five.

Malcolm Nance, a former US Navy intelligence specialist with experience in Iraq, told Newsweek that the identities of US special operation forces are typically kept secret.

"Operational security is the most important aspect of personnel deployments. The real names, faces, and identities, of personnel involved in special operations or activities, are usually a closely held secret in a combat zone," he said.

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"Revealing them casually, through an unusual media exposure even if it’s the commander in chief, would prove a propaganda boom if any of this personnel are detained by a hostile government or captured by a terrorist group. There would be no denying who you are and what you do."

An anonymous Defense Department official also told Newsweek that the faces of special operations forces are typically blurred — even when they are pictured with the president or vice president.

"I don't recall another time where special operation forces had to pose with their faces visible while serving in a war zone," they added.

Trump tweeted the video after his secret trip to see to US troops in Iraq — his first visit to meet with US forces serving in a combat zone since he took office.

Read More: 'Embarrassing' and 'entirely inappropriate': One of the most highly decorated former US Army generals blasts Trump's visit with US troops in Iraq

He came under fire, including from a former US Army four-star general, for signing pieces of campaign memorabilia for the troops, including hats emblazoned with the "Make America Great Again" campaign slogan.

Trump said that he has "no plans at all" to withdraw US forces from the country, where they've been present since the 2003 invasion.