On the campaign trail, Mayor Pete Buttigieg, a Democratic presidential hopeful, frequently anchors his stump speeches and interviews in a message of unity and bringing the whole country together, but over the last week, his sharper rhetoric aimed at Vice President Mike Pence has brought their complicated relationship under scrutiny.

“I’m not interested in feuding with the vice president, but if he wanted to clear this up, he could come out today and say he’s changed his mind that it shouldn’t be legal to discriminate against anybody in this country for who they are. That’s all,” the South Bend mayor, who is gay, said on “The Ellen DeGeneres Show” Friday.

Over the last week, a public clash between Buttigieg and Pence about the former Indiana governor’s controversial views on gay marriage and the role of faith in the conversation has escalated as both continue to address the squabble in separate but back-to-back TV interviews.

“I hope that Pete will offer more to the American people than attacks on my Christian faith or attacks on the president as he seeks the highest office in the land," Pence said in an exclusive interview with CNN Friday.

In this May 1, 2015, file photo, then-Indiana Gov. Mike Pence, right, talks with South Bend Mayor Pete Buttigieg during a visit to recap the legislative session that ends in South Bend.(Robert Franklin/South Bend Tribune via AP) In this May 1, 2015, file photo, then-Indiana Gov. Mike Pence, right, talks with South Bend Mayor Pete Buttigieg during a visit to recap the legislative session that ends in South Bend.

When pressed about the Harvard University graduate’s comments and about if he considers being gay a sin, Pence said, “All of us have our own religious convictions. Pete has his convictions, I have mine.”

“I’m a Bible-believing Christian. I draw my truth from God’s word,” he added.

“I’m not critical of his faith,” Buttigieg said in the interview with DeGeneres. “I’m critical of bad policies. I don’t have a problem with religion. I’m religious too. I have a problem with religion being used as a justification to harm people and especially in the LGBTQ community.”

Buttigieg and Pence overlapped in their shared home state’s political sphere between 2013 and 2017 and during that time, the two appeared to have a civil working relationship. In 2015, Pence signed the controversial Religious Freedom Restoration Act into law, a measure which many in the LGBTQ community feared would allow businesses to deny them services.

"We worked very closely together when I was governor and I considered him a friend," Pence told CNN. "He knows I don't have a problem with him. I don't believe in discrimination against anybody. I treat everybody the way I want to be treated."

Their relationship is receiving renewed attention as Buttigieg’s long-shot White House bid is increasingly gaining national prominence.

In recent polls, Buttigieg stands in third among Iowa’s and New Hampshire’s Democratic voters, and tied for fourth with Sen. Elizabeth Warren, D-Mass., among California’s Democratic voters. He’s also outpaced several well-known Democratic competitors including Warren and Sens. Cory Booker, D-N.J, and Amy Klobuchar, D-Minn, in fundraising, raking in nearly $7 million in the first quarter.

Buttigieg began trading barbs with the vice president on Sunday, when he told the crowd at an LGBTQ event, “If me being gay was a choice, it was a choice that was made far, far above my pay grade. That's the thing I wish the Mike Pences of the world would understand. That if you got a problem with who I am, your problem is not with me -- your quarrel, sir, is with my creator."

President Donald Trump and Vice President Mike Pence arrive at the Capitol to attend the weekly Republican Senate policy luncheon, Jan. 9, 2019.(Alex Wong/Alex Wong/Getty Images, FILE) President Donald Trump and Vice President Mike Pence arrive at the Capitol to attend the weekly Republican Senate policy luncheon, Jan. 9, 2019.

Pence's press secretary immediately responded to Buttigieg's comments, writing in a tweet, "The last time we recall Pence even mentioned @PeteButtigieg was in 2015, after news that Pete came out, Pence said: 'I hold Mayor Buttigieg in the highest personal regard. I see him as a dedicated public servant and a patriot.'"

Pence first responded to Buttigieg in an interview with CNBC Thursday, saying they had a “great working relationship” and criticized how the mayor characterized his “Christian values.”

“I get it you know, it’s like — you have 19 people running for president on that side in a party that’s sliding off to the Left,” Pence said. “ He knows better. He knows me.”

Pence later added during the interview with CNN, “Pete’s quarrel is with the First Amendment.”

The 37-year-old mayor, who announced his exploratory committee in January, has frequently criticized Pence for his views on LGBTQ issues, calling him a “cheerleader of the porn star presidency” and criticized him for turning a blind eye towards President Donald Trump, who has been accused of sexual misconduct by several women.

Buttigieg is poised to officially enter the 2020 contest on Sunday at a rally in his hometown.

In the first few months of the race, he has emerged from the crowded bench as a moderate voice, who is also confronting the conversation over religion and sexuality in atypical fashion. For many of the presidential candidates, Trump remains the primary foil, but for Buttigieg, he’s chosen to pivot his attacks towards his fellow Hoosier.

As Buttigieg’s rhetoric toward Pence hardens, he’s been celebrated by the LGBTQ community.

“Mike Pence is an anti-LGBTQ extremist who falsely uses religion to justify bigoted policies that harm LGBTQ Americans – whether they are of faith or not,” said Annise Parker, president and CEO of LGBTQ Victory Fund. “Mayor Pete is rightfully speaking out about his own religious beliefs and saying it is inexcusable for Mike Pence to impose his warped view of religion on all Americans and strip LGBTQ people of their rights.”

ABC News' Justin Gomez contributed to this report.