Vice President Mike Pence said Thursday that Pete Buttigieg, the mayor of South Bend, Indiana, and upstart presidential hopeful, had criticized his positions on gay marriage and LGBTQ equality to stand out among a crowded Democratic primary field.

“Well, look, I worked very closely with Mayor Pete when I was governor of the state of Indiana," Pence said in an interview on CNBC’s “Squawk Box.” "We had a great working relationship, and he said some things that are critical of my Christian faith and about me personally, and he knows better, he knows me.”

“I get it, you know, it's like, you have 19 people running for president on that side, and part of it is sliding off to the left,“ he added. “They're all competing with one another for how much more liberal they can be. I get that.”

Pence was asked in the CNBC interview about the landmark Supreme Court decision in 2015 that legalized gay marriage nationwide and whether he had “accepted it’s law.”

The vice president replied that he “fully implemented that decision in the law” as governor, “but … I have my Christian values.”

“My family and I have a view of marriage that's informed by our faith, and we stand by that," he said. "But that doesn't mean that we're critical of anyone else who has a different point of view. One of the great things about this country is our freedom of religion and the freedom of conscience, and we'll continue to cherish our values, cherish our views.”

Pence has opposed gay rights policies such as legalizing same-sex marriage, and in 2015, as Indiana governor, he signed the state’s Religious Freedom Restoration Act, which critics have said gives businesses the right to refuse service to gay people.

As governor, Pence praised Buttigieg after he came out publicly in 2015. But Buttigeig, who is in a same-sex marriage, has criticized the vice president in recent weeks as attention on his long-shot presidential bid has escalated.

In a speech before an audience of LGBTQ rights supporters on Sunday, Buttigieg said, “If being gay was a choice, it was a choice that was made far, far above my pay grade.”

“And that’s the thing I wish the Mike Pences of the world would understand. That if you have a problem with who I am, your quarrel is not with me. Your quarrel, sir, is with my creator,” Buttigieg said.

He added that his marriage to his husband “has made me a better man, and yes, Mr. Vice President, it has moved me closer to God.”

Buttigieg reprised his critique on Monday.

“Just because you are LGBTQ doesn't mean it's OK to discriminate against you,” he told reporters in Las Vegas. “I think most people get that, I think most Christians get that, and it's time for us to move on toward a more inclusive and more humane vision of faith than what this vice president represents."