The 69-year-old French civil servant has been in charge of all negotiations between the European Union and the United Kingdom, after the latter requested to leave the political bloc in March 2017.
Barnier tweeted that he’s “doing well and in good spirits.”
“I am following all the necessary instructions, as is my team. For all those affected already, and for all those currently in isolation, we will get through this together,” he added.
The European Commission was not immediately available for comment when contacted by CNBC.
Barnier had been leading the second phase of negotiations between the EU and the UK these started earlier this month, with the aim of putting together a trade deal before the end of the year.
A UK government spokesperson said Thursday that Downing Street sent Barnier their best wishes, Reuters reported. Thursday’s announcement will no doubt raise questions on the timetable for the negotiations, as UK Prime Minister Boris Johnson has vowed not to extend trade talks beyond 2020.
UK and EU negotiating teams were due to meet in London next week, but these talks have been canceled due to the COVID-19 pandemic