“Haley Barbour is a great citizen; he’d have made a great president,” Daniels, the Indiana governor, said in a statement. “I’d have been proud to try to help him had he chosen to run.”

Daniels, who first became friends with Barbour when they served together as 30-somethings in the Reagan White House added: “The Barbours have been close and true friends to the Daniels family, and we will always be 100 percent supportive of any decision they believe is best for them.”

Daniels has said in the past that he would likely not run if Barbour is in the race.

“My first inclination would be to help Haley,” said Daniels in a December interview with POLITICO, adding: “It would be unusual [if we both ran].”