Updated at 2:15 p.m. EDT

President Trump's national security adviser Robert O'Brien has tested positive for the coronavirus, the White House announced on Monday.

"National Security Adviser Robert O'Brien tested positive for COVID-19. He has mild symptoms and has been self-isolating and working from a secure location off-site. There is no risk of exposure to the president or the vice president. The work of the National Security Council continues uninterrupted," the White House said in a statement. No further details were immediately available.

President Trump told reporters at the White House that he had not had any recent contact with the 54-year-old O'Brien. "I haven't seen him lately," Trump said. "I'm calling him later."

O'Brien is the most senior White House official known to get the virus, and the closest to Trump. He is the latest person in Trump's orbit to become infected.

In May, Katie Miller, the spokeswoman for Vice President Pence who is married to a senior Trump adviser, tested positive, as did a military aide who worked as a valet to the president. In June, eight members of the campaign's advance team, including two Secret Service agents, tested positive in Tulsa, Okla., just before a Trump rally there. Kimberly Guilfoyle — a fundraiser for the campaign and the girlfriend of Trump's son, Donald Trump Jr. — tested positive in early July.

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