Arizona Senator Jeff Flake, a Republican, said Sunday that he could someday back a GOP presidential candidate who supports gay marriage.

Appearing on NBC News' Meet The Press, guest host Chuck Todd asked Flake, “Could you support a Republican presidential candidate someday who supported same-sex marriage?”

“Oh, I think that's inevitable,” Flake answered. “There will be one, and I think he'll receive Republican support, or she will. So I think that yes, that the answer is yes.”

When pressed on whether he supports such unions, Flake replied that he does not.

“And where are you on this issue, you say it's inevitable. Are you … Lisa Murkowski, a Republican colleague of yours, called it evolving on the issue. Are you evolving, to use her words, on this issue?” Todd asked.

“I believe that marriage should be between a man and a woman. I still hold to the traditional definition of marriage.”

“Can you imagine changing your position before you left the U.S. Senate?”

“I can't,” Flake said. “I tell you, in the past I've supported repealing 'Don't Ask, Don't Tell.' I've supported the [Employment] Nondiscrimination Act [ENDA] as well. But I hold to the traditional definition of marriage.”

(Watch the entire segment at NBC News.)