The location of such a deployment, as well as the identities or identifiable faces of service members, are usually classified, Defense Department sources told Newsweek magazine.
A president has the power to declassify such information, but Trump's exposure of the team online was apparently inadvertent, USA Today reported.
According to the pool report of the president's trip to Iraq, Trump asked the chaplain of Seal Team 5 to pose for a picture with him. Trump and first lady Melania Trump also posed for a photo with several other members of the team. The president later posted a video of the meeting to his Twitter account, revealing the faces of the team members and noting the presence of the team at the al-Asad Airbase in western Iraq:
The Office of the Secretary of Defense told NBC that no rules were violated by Trump's tweets.
"The special operators voluntarily participated in this open press event," the office stated. "There was no security violation."
But an unnamed Defense Department official and other sources told Newsweek that the "deployments of special operation forces — including Navy Seals — are almost always classified events, as to protect those men and women that are on the front lines of every overt and covert conflict."
The official also said that even in the event of special ops demonstrations for congressional delegations, service members' faces are either covered or "digitally blurred" in film and photos to shield information from the public.
The official couldn't recall a similar event with another president in which the team's identities weren't shielded.
Retired U.S. Navy Admiral James Stavridis said on MSNBC Thursday that he was surprised by the photo of the Navy Seal chaplain.
"It's important he's a Seal," Stavridris said. "That's a part of the force that is historically supposed to be very, very cloistered, very much in the shadows."
Retired U.S. Navy Chief Petty Officer Malcolm Nance, who now serves as an intelligence consultant for U.S. special operations forces, told NBC that the Seals' identities should not have been revealed.
"The fact is they are a special operations force in a combat zone with a combat role. The reason their identities are protected is in case of capture," Nance said.
The president's actions sparked anger on Twitter:
Critics have slammed Trump's visit to Iraq to meet with American troops and accused him of politicizing the military. During his visit, Trump called out Rep. Nancy Pelosi (D-Calif.) for not supporting his border wall, pushed his isolationist policies and signed MAGA campaign hats.
"It's like the politicization of the judicial branch," said retired three-star Army Lt. Gen. Mark Hertiling per The New York Times. "He has to understand that there exist some audiences that should not be addressed as part of his base because they are not. It's a violation of protocol by the president."
This article originally appeared on HuffPost.