French President Francois Hollande acknowledged on Sunday there was a threat of an attack during the Euro 2016 football championship but said the country must not be intimidated. He also issued an appeal for a halt to transport strikes that threaten to disrupt the month-long football extravaganza opening on Friday.
"This (attack) threat exists," he told public radio France Inter. "But we must not be daunted.
"We must do everything to ensure that the Euro 2016 is a success."
The country is on high alert for possible terror strikes during the football extravaganza opening on Friday, following the jihadist attacks in Paris in January and November last year.
The United States warned last week of the risk of attacks, with the French stadiums hosting the matches but also the so-called fan zones where spectators will be gathering in large numbers potential targets.
France has also been in the grip of nation-wide protests and transport strikes over controversial labour reforms, with the sense of malaise compounded by flooding in the Paris region.
A final round of negotiations is due to take place between French rail operator SNCF and the government in a bid to break a five-day strike that has blocked trains and created transport chaos across the country.
And Air France pilots are threatening to start a four-day strike on June 11, when the Euro tournament is in full swing, and a major protest is planned in Paris on June 14.
"No-one would understand if the trains or the planes... prevented the smooth transport... of spectators."