French President Emmanuel Macron has tested positive for Covid-19 after a week of meeting numerous European leaders.
The French and Spanish prime ministers are among those self-isolating because they had recent contact with him.
Mr Macron took a test “as soon as the first symptoms appeared” and will self-isolate for seven days, the presidency said in a brief statement.
It did not detail what symptoms Mr Macron experienced or any treatment he might be receiving.
The 42-year-old president “will continue to work and take care of his activities at a distance”, the statement added.
His wife, Brigitte, 67, will also self-isolate but has no symptoms and tested negative on Tuesday ahead of a visit to a Paris hospital, her office said.
French government spokesman Gabriel Attal said contact tracing efforts are in progress.
He said Mr Macron started to feel symptoms overnight and he will keep working from the Elysee presidential palace.
“The virus has been circulating in France and worldwide for several months and the presidency and government are used to working in these circumstances,” Mr Attal said.
Mr Macron has joined a growing list of world leaders who have tested positive for the virus, including US President Donald Trump and UK Prime Minister Boris Johnson, who wished him well on Twitter.
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.
France has a tradition of keeping strict medical privacy, including for top officials, and Mr Macron once said he would release health information only when justified by the impact it could have on his presidency.
He has rarely been seen in public without a mask in recent months, only removing it when making a speech or at a press conference when he is at safe distance from others.
The French president has had multiple in-person meetings in recent days at home and in Brussels, where he attended a European Union summit at the end of last week.
The Elysee palace confirmed a trip to Lebanon scheduled for next week is being cancelled.
EU leaders met in person in Brussels on December 10-11, for the first time since October.
TV images showed the leaders wearing masks, generally keeping good distance and preferring elbow bumps to the usual handshakes, kisses and hugs – and occasionally using handgel dispensers in the room.
“During the European Council of Thursday December 10 and Friday December 11, all sanitary measures were observed and we have not been informed of any other participant or staff present during the summit who tested positive,” an EU official said.
The Spanish government has announced Prime Minister Pedro Sanchez, who met Mr Macron in Paris on Monday, will place himself in quarantine until December 24.
Mr Sanchez informed Spain´s King Felipe VI of the decision and cancelled an appearance at Spain’s National Library on Thursday.
Portugal Prime Minister Antonio Costa, who had lunch with Mr Macron on Wednesday, has taken a Covid-19 test, has shown no symptoms and is in self-isolation awaiting the result, his office said.
Mr Costa has cancelled an official three-day visit to west Africa from Friday, as well as his attendance at all other events.
European Council President Charles Michel and several other EU top officials announced they are placing themselves into self-isolation as a precaution.
German Chancellor Angela Merkel, who had a bilateral meeting with Mr Macron in Brussels, took a PCR test a few days after the European Council meeting as a matter of routine and it was negative, her office said.
Mr Macron’s positive test also led several high-profile French politicians and government officials to self-isolate out of a precaution.
Mr Macron held the government’s weekly Cabinet meeting on Wednesday.
A day earlier, Mr Macron had lunch with the heads of political groups at the National Assembly, France’s lower house of parliament.
French Prime Minister Jean Castex’s office said he will now self-isolate for seven days.