The countdown to the tournament began as Euro 2016 organisers unveiled the logo of the continental competition which twice winners France will host for the third time, after the first edition in 1960 and a home triumph in 1984.
The qualification draw will take place on Feb. 23 next year, with 53 national teams competing to be among the 24 finalists.
"I think that all the stadiums will be ready," Frenchman Platini, who scored a record nine goals in the 1984 event, told reporters.
"Lyon [stadium] is going to be built, Lens looks like it will be done, I don't think there will be a problem," he added.
"We can't imagine having the Euro in France without Lyon but when France need to do something, they do it," UEFA's General Secretary Gianni Infantino said.
"We really trust France. We staged the last Euro in Poland and Ukraine and it had not been easy. It's a completely different situation here because France already have all the infrastructure. Apart from stadiums, there's nothing to build."
"On average, French stadiums date back to the 1950s. I remind you that we're investing 1.7 billon euros. I think we can dream of catching up Germany," French league president Frederic Thiriez said.
