It is the first time Wales and France have gone head to head in the history of the competition and Roberts reckons France will come out firing at Eden Park.
“We are meeting a French side in the semi-final of a World Cup and it doesn’t get much bigger for any side or any individual,” he said.
“It is going to be a colossal battle.
“It’s a semi-final of a World Cup and it’s the biggest game that we have played in but we have to remember its simply another game of rugby and focus on that.
“We have worked very hard to get here and are on form but France have beaten us the last couple of times we have played. And for neutral fans it’s a toss of a coin who goes through and that is what makes this tournament.
“We are very strong physically and mentally and that is what can make the difference. But we are expecting a French team who will offer everything in attack and give everything in defence.”