The Euro 2016 soccer championships has begun amid unprecedented security.
France is under a state of emergency since terror attacks last November in which 129 people died.
90,000 police and other personnel have been drafted to patrol stadiums and fans zones.
Over 100,000 football fans from Ireland are expected to travel to France for the games.
Hosts France kicked off the tournament with a 2-1 win over Romania at the Stade de France.
Northern Ireland face Poland at the Stade de Nice on Sunday while the Republic of Ireland play their first game against Sweden in Stade de France on Monday.
France's Ambassador to Ireland, Jean-Pierre Thébault, has said that he is confident French authorities have made the best preparations possible.
Mr Thébault said that authorities will try to avoid lengthy security checks for fans, but added that it is important that everyone participates, describing fans as the actors of their security.
He advised fans to carry an ID and suggested downloading the various iphone and android security apps, highlighting SAIP.
The Ambassador said that security measures should not deter fans from enjoying their experience in France, saying they can expect an incredible welcome.
One group of Irish fans who have spruced up an old Dublin bus are hoping to pick up "stragglers" on their trip around France.
Andy Bennett, from Malahide, said he and his friends are keen to welcome people on board their bus, which ferried passengers around the Irish capital in 1991.
He sets off for France this weekend and he said: "I'm so excited. I can't stop thinking about it."
There is no shower on the bus, but it does have two toilets and a "hose".
"The bus is in really good condition. It's got a couple of toilets on it. There's no shower but there's a generator and I guess you'd call it a hose," he said.
The top deck of the bus contains camp beds, while the immortal words "Oh la la la Paul McGrath" are emblazoned on the side.
While Mr Bennett had hoped to round up 11 friends for the footballing bus tour, that has not been possible due to other commitments.
As a result, he said "the plan is hopefully to pick up some stragglers along the way. We're going to have obviously seven spare beds."
Another decommissioned Dublin Bus, this time bearing the iconic image of Daniel O'Donnell, is also making the journey from Dundalk to France for the tournament.
A huge open-air concert welcoming Euro 2016 was held in front of the Eiffel Tower last night.
Meanwhile, French President Francois Hollande has warned unions not to try to disrupt the championships.
France has been hit by industrial action in protest at Mr Hollande's reforms of employment laws.
He said everyone has a responsibility to ensure the event runs smoothly.
The Irish Embassy in France has an emergency helpline for anyone who may need urgent assistance during the tournament.
Minister for Foreign Affairs Charlie Flanagan has also urged Irish fans travelling to France to exercise caution.
Mr Flanagan said he was always very concerned when Irish people travelled to any country with a state of emergency.
He said fans should carry identification at all times and expect to be stopped and searched.
The Laois TD was speaking at the launch of a new smartphone travel app from the Department of Foreign Affairs.
The Travelwise app features travel advice, security updates and consular information on 200 countries worldwide.
