(CNN) President Donald Trump's national security adviser, Robert O'Brien, has tested positive for Covid-19, according to an official familiar with what happened. O'Brien's diagnosis marks the highest-ranking Trump administration official known to have tested positive. Several National Security Council staffers told CNN that they weren't informed that O'Brien tested positive and learned of the news from media reports. A source familiar said O'Brien was last in the office last Thursday, when he abruptly left the White House. The White House statement said there is "no risk of exposure to the President or the Vice President."

Source: CNN July 27, 2020 13:07 UTC