Mr. Johnson, 55, went into isolation after experiencing mild symptoms of illness, his office said Friday.
British Prime Minister Boris Johnson announced on Friday that he is self-isolating after testing positive for COVID-19.
A Downing Street spokesperson said in a statement that Johnson, whose partner Carrie Symonds is pregnant, experienced mild symptoms on Thursday and was tested for COVID-19 on the personal advice of England's chief medical officer.
The government confirmed this week that if Johnson was incapacitated, Foreign Secretary Dominic Raab would temporarily assume the role of prime minister.
Mr. Johnson, 55, went into isolation after experiencing mild symptoms of illness, his office said Friday.
