The Pentagon on Thursday once again updated the number of US service members diagnosed with traumatic brain injuries to 64 in Iran’s missile attack on an Iraqi air base earlier this month.

The number increased from just two days ago, when the Pentagon said 50 troops had been hurt. Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff, said at a news conference that all 64 are categorized as “mild” injuries.

But, in some cases, “we’ll continue to monitor them for the rest of their lives and continue to provide whatever treatment is necessary,” Milley told reporters.

Of the 64 injured, 39 have returned to duty, officials said. Twenty-one have been transported to Germany for further evaluation and treatment.

A little over a week after the Jan. 8 attack, the military had said 11 service members were injured with “concussion symptoms from the blast.”

Then, on Jan. 24, officials updated the number of injured troops to 34.

Milley said it’s possible symptoms of traumatic brain injury, or TBI, stemming from the Jan. 8 strike won’t become apparent for a year or two.

“We’re early in the stage of diagnosis, we’re early in the stage of therapy for these troops,” Milley said.

The missile attack on the Al Asad air base was carried out by Iran in retaliation for the US drone strike that killed its top general, Qassem Soleimani, on Jan. 3.

President Trump initially said no US service members were injured or killed — a discrepancy the military attributed to symptoms not being immediately reported or, in some cases, only becoming known days later.

“[TBI] manifests itself over time … I still believe that morning there were no casualties reported,” Defense Secretary Mark Esper said at the press conference Thursday.

The Pentagon is studying ways to improve diagnosis and treatment and also to prevent brain injuries on the battlefield, Esper told reporters.

When the Pentagon reported Jan. 17 that the 11 injured troops had been evacuated out of Iraq, Trump said, “I heard they had headaches and a couple of other things … and I can report it is not very serious.”

The comments prompted criticism from some lawmakers and veterans groups.

TBI has become a larger concern for the military in recent years. It can impair thinking, memory, vision, hearing and other abilities. Severe cases can result in coma, amnesia or death.

During Thursday’s news conference, Esper defended the president, saying Trump “understands the nature of these injuries.”

“I’ve had the chance to speak with the president, he is very concerned about the health and welfare of all of our service members, particularly those who were involved in the operations in Iraq, and he understands the nature of these injuries,” Esper said.

With Post wires