WASHINGTON – President Donald Trump’s national security adviser, Robert O’Brien, has tested positive for COVID-19, officials said Monday, becoming the highest-ranking administration official to contract the disease.

The news came days after the announcement that a Marine assigned to the military unit that flies Marine One tested positive for coronavirus but did not have direct contact with Trump or his presidential helicopter.

O’Brien, who was named national security adviser in September, “has mild symptoms and has been self-isolating and working from a secure location off site,” the White House said in a statement, asserting that there was no risk to the president or the vice president of exposure.

“The work of the National Security Council continues uninterrupted,” the statement read.

Trump could not recall the last time he met with O’Brien and did know exactly when his top security adviser tested positive.

I haven’t seen him lately,” Trump told reporters at the White House.

Trump and O’Brien were last seen in public together during a July 10 visit to the U.S. Southern Command in South Florida. The next week, O’Brien traveled to Paris for meetings with counterparts from France, the United Kingdom, Germany and Italy.

The White House also conducted contact tracing last week after an employee for a cafeteria vendor at the two eateries inside the Eisenhower Executive Office Building tested positive for the coronavirus.

Katie Miller, a top spokeswoman for Vice President Mike Pence, tested positive in early May and has since returned to work.

National Security Adviser Robert O'Brien.