Calzaghe had been in Las Vegas to support Ricky Hatton as the Manchester fighter lost in the tenth round to Floyd Mayweather on Saturday.
Warren had earlier issued a statement that read: "I want the fight, the fans want the fight and [cable TV company] HBO want the fight, so there's no reason for it not to happen."
Welshman Calzaghe was involved in a slanging match with Hopkins at the MGM Grand last week after they went head-to-head at the weigh-in for Hatton v Mayweather.
"Coming face-to-face with Hopkins over the weekend made me want the fight even more," said Calzaghe.
"I'll go to America and take the fight, no problem at all. Bernard's a great fighter, but he's not as good as me.
"2007 has been a fantastic year for me, what with beating Kessler and then winning the BBC award on Sunday night.
"I've got my fingers crossed that 2008 will be even better, with a fight against Hopkins, and a win that will finally show everyone in America that I deserve all the praise I get."