The organisers of Euro 2016 have increased the security budget for the tournament by 15 percent in the aftermath of the Paris terrorist attacks.
In November, 130 people were killed in a series of bombings and shootings across the French capital.
Speaking at a news conference to mark 100 days until the tournament, organising president Jacques Lambert said on Wednesday the security budget had been increased to €34 million.
France remains in a state of emergency which has been extended until May 26, two weeks before the tournament begins on July 10.
About 10,000 people have been privately hired for security work, with 900 agents mobilised for each of the 51 matches. Organisers are in charge of security within stadiums, with the French authorities dealing with it outside.
"Security is our essential preoccupation, but I don't lose sleep over it -- we are handling it with cold blood," Lambert, who was in charge of security when France hosted 1992 Winter Olympics, said.
Security at team hotels will also be heightened, while fans will undergo two security checks when entering stadiums.
A first perimeter will be set up away from the gates, where spectators will have their tickets checked and be submitted to body searches. Lambert said fans would be thoroughly checked once at turnstiles.
Lambert added that Euro organisers would take over security issues at the 10 stadiums hosting matches by mid-May.
"From then, an accreditation will be required to enter the venues," he said. "These accreditations will only be granted after a screening done by public authorities."
UEFA said on Tuesday that Euro games could be moved to different venues in France and rescheduled without crowds in response to any terror attacks or threats.
However, Lambert said they were not thinking of playing matches behind closed doors at this stage.
Security at fan zones will also be increased. About seven million supporters visited the fan zones in the host cities during Euro 2012 in Ukraine and Poland, and there are concerns the designated Euro 2016 areas for the public could be targeted by attackers.
While there has been a significant drop in tourism since the attacks, Lambert said ticket sales for the Euro were not affected, with about 1.5 million fans from abroad expected in France during the tournament.
"There has not been any panic," he added. "We did not receive any request for ticket refund."
A total of about 2.5 million tickets will be sold, with organizers expecting to make about €250m through ticket sales.