US President Donald Trump's national security adviser Robert C O’Brien has tested positive for coronavirus, the White House said Monday.

The Washington Post reports that O’Brien is the highest-ranking Trump administration official known to have tested positive for Covid-19.

The White House said in a statement that O'Brien, 54, has "mild symptoms" and has been self-isolating, adding there was no risk of exposure to Trump, Bloomberg reported. O’Brien contracted the virus while taking a few days off from work to spend time with his family, the report read. 

O’Brien and senior staff in the White House are tested daily for Covid-19, according to Bloomberg's report.

At least 143 000 people have died of Covid-19 to date in the US, amounting to approximately one-fifth of the world’s death toll. The country has more than 4 244 600 cases.