French President Emmanuel Macron has tested positive for Covid-19, the presidential Elysee Palace announced.
It said the president took a test “as soon as the first symptoms appeared”.
The brief statement did not say what symptoms Mr Macron experienced.
It said he would isolate for seven days, adding: “He will continue to work and take care of his activities at a distance.”
It is not immediately clear what contact tracing efforts are in progress.
Mr Macron attended a European Union summit at the end of last week, where he notably had a bilateral meeting with German Chancellor Angela Merkel.
He met the prime minister of Portugal on Wednesday.
There was no immediate comment from Portuguese officials.
UK Prime Minister Boris Johnson, who had Covid-19 earlier in the year, tweeted his support for the French president.
Mr Johnson said: “Sorry to hear my friend @EmmanuelMacron has tested positive for coronavirus. We are all wishing you a speedy recovery.”
He then repeated the message in French.
Mr Macron also held the French government’s weekly Cabinet meeting on Wednesday in the presence of Prime Minister Jean Castex and other ministers.
Mr Castex’s office said the prime minister is also self-isolating for seven days.
The French presidency confirmed Mr Macron’s trip to Lebanon scheduled for next week is being cancelled.
Mr Macron and other government officials have repeatedly said they have been sticking to strict sanitary protocols during the pandemic, including not shaking hands, wearing a mask and keeping distance from other people.
The president is following French health authorities’ recommendations that since September have reduced the self-isolation time from 14 days to seven.
Authorities said at the time this is the period when there is the greatest risk of contagion and that reducing it allows better enforcement of the measure.
French health authorities argued this week that the 14-day quarantine was not well-respected by many in the country who considered it too long.