A major veterans group called on President Donald Trump to apologize for remarks the group said minimized the traumatic brain injuries suffered by U.S. service members in a Jan. 8 Iranian missile attack in Iraq.

The head of the Veterans of Foreign Wars, William "Doc" Schmitz, said in a statement Saturday that the organization "expects an apology from the president to our service men and women for his misguided remarks."

After the attack on two bases housing U.S. troops, Trump said there had been no casualties. But the Department of Defense later announced that 11 service members were being treated for concussions caused by blast waves from the ballistic missiles. On Friday, Pentagon spokesman Jonathan Hoffman told reporters that a total of 34 service members had been diagnosed with concussions and traumatic brain injuries.

In light of that announcement, "and President Trump's remarks which minimized these troops’ injuries, the Veterans of Foreign Wars cannot stand idle on this matter," Schmitz said.

Schmitz was referring to comments Trump made in a news conference during his trip last week to the World Economic Forum in Davos, Switzerland. Trump downplayed the severity of the troops' injuries, saying, "I heard that they had headaches, and a couple of other things, but I would say, and I can report, it's not very serious."

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"I don’t consider them very serious injuries, relative to other injuries that I’ve seen," Trump said. "No, I do not consider that to be bad injuries."

In addition to the apology, the group called on the White House to help educate the American people about the dangers posed by brain injuries.

"TBI is a serious injury and one that cannot be taken lightly," the VFW statement said.

"TBI is known to cause depression, memory loss, severe headaches, dizziness and fatigue – all injuries that come with both short- and long-term effects."

The VFW has more than 1.6 million members, according to its website.

Iran launched the missile attacks in retaliation for a U.S. drone strike that killed its top general, Qasem Soleimani, outside the Baghdad airport. In the wake of Soleimani's death, the world feared the Iranian response could lead to open conflict between the U.S. and Iran.

Trump had vowed that any attack on U.S. troops or assets were would be met with a massive response.

In an address to the nation following the missile attack, Trump said, "The American people should be extremely grateful and happy no Americans were harmed in last night’s attack by the Iranian regime."