A senior defense department official who attended last year's NATO summit at Vilnius, Lithuania, had symptoms similar to those reported by US officials who have experienced “Havana syndrome," the Pentagon confirmed on Monday.

Havana syndrome is still under investigation but includes a string of health problems dating back to 2016, when officials working at the US Embassy in Havana reported sudden unexplained head pressure, head or ear pain, or dizziness.

The injuries to key US government personnel or their families were part of a “60 Minutes” report Sunday that suggested Russia is behind the incidents, one of which took place during the 2023 NATO summit at Vilnius.

“I can confirm that a senior DOD official experienced symptoms similar to those reported in anomalous health incidents,” deputy press secretary Sabrina Singh told reporters Monday. Singh referred questions on whether Russia had a role to the intelligence community, which is still investigating the matter.

The official, who was not identified, was not part of Defense Secretary Lloyd Austin's official travelling delegation to Vilnius, Singh said, but was there “separately, attending meetings that were part of the NATO summit."

Singh did not say whether the affected defense official had to seek further medical care, retire or cease performing duties, citing medical privacy.

In February the Office of the Director of National Intelligence in its 2024 threat assessment found that it was “unlikely” that a foreign adversary was responsible for causing the mysterious ailments but noted that US intelligence agencies had varying levels of confidence in that assessment.

The Pentagon's health care system has established a registry for employees or dependents to report such incidents.

In March, however, a five-year study by the National Institutes of Health found no brain injuries or degeneration among US diplomats and other government employees who had Havana syndrome symptoms.