Francoise Hollande
Francoise HollandeIssam Rimawi/Flash 90

French President Francois Hollande acknowledged on Sunday there was a threat of an attack during the upcoming Euro 2016 soccer championship, but said the country must not be intimidated.

"This (attack) threat exists," he was quoted by AFP as having told public radio France Inter. "But we must not be daunted. We must do everything to ensure that the Euro 2016 is a success."

France is on high alert for possible terror strikes during the tournament opening on Friday, following 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.

In fact, in April it was revealed that the Brussels, Belgium bombing cell planned to attack the Euro 2016 soccer cup. 

Prosecutors revealed that the cell - which includes dozens of Islamists, many of whom are related - had not initially chosen Brussels' airport and metro stations as a target, but had initially planned a mass terror attack in France.

Brussels bomber Mohamed Abrini revealed after his arrest that the true target was the Euro 2016 cup, which will be held in 10 different locations throughout the country and beginning and ending in Paris. 

Ahead of the Euro 2016, France simulated a terrorist attack at a fan zone in preparation for the tournament.

The country, like many others in Europe and throughout the world, has been affected by the phenomenon of radicalization.

In April, 12 members of a France-based jihadist network that sent fighters to Syria were given prison sentences, including a woman who had taken her three children to join her husband there.

In January, a key French member of ISIS who had ties to the Charlie Hebdo attackers was sentenced in absentia by a Paris court to 15 years in prison.

Other countries dealing with radicalized locals who join jihadists in Iraq and Syria include GermanySpainSwedenBelgium and Britain.