Democratic presidential contender Pete Buttigieg is planning a hefty new ad buy in South Carolina as his campaign seeks to build up support among black voters, who have so far been skeptical of the young mayor.

The campaign is kicking off a $2 million media blitz in the state with a 60-second radio spot highlighting Buttigieg's military service in Afghanistan, it said in a release.

Buttigieg also pledges in the ad to "tackle systemic racism wherever we find it until your race in this country has no bearing on your health, or your wealth, your life expectancy or your relationship with law enforcement."

In addition to the radio ad, the campaign plans to roll out television advertisements, NBC News reported.

The 37-year-old Democrat has seen a recent surge in Iowa, which has a small minority population, but has had less success garnering the support of black voters in critical early primary states that are more diverse.

Buttigieg is in sixth place in South Carolina, polling in the low single digits, according to an average of state polls tallied by Real Clear Politics.

Read more: Pete Buttigieg met with Black Lives Matter after a police shooting. It didn't go well

Iowa's population is about 4% black, according to Census figures. In South Carolina, in contrast, more than one in four residents are black. Black voters are more likely to be Democrats, making the voting bloc even more essential in the party's primary process.

The campaign has said that it is intent on developing support among black voters but has faced a number of hurdles.

Buttigieg's record on race as mayor has come under scrutiny as his profile has risen, including a controversial episode in which he fired his city's first black police chief. Buttigieg has said that he fired the chief because he was under investigation, though activists in the city continue to doubt his sincerity.

The fatal police shooting of Eric Logan, a black father, by a white South Bend police officer in June deepened the candidate's problems.

The campaign rolled out an 18-page plan to combat systemic racism in July. In September, Politico reported the campaign had hired a black outreach director.

A consulting firm hired by the mayor's campaign, which conducted focus groups of black South Carolina primary voters, also found that Buttigieg's sexuality could be a barrier. Buttigieg is the first openly gay Democratic presidential candidate.

The firm said that the black voters it spoke with found Buttigieg's "eloquence and presentation style to be appealing" but "are going to need to see real demonstrations of broad enthusiasm and likely some endorsements from 'cool' black people to help them believe that 'other people' don't have a problem" with his sexuality.

The focus group study was first reported by the State newspaper.

Former Vice President Joe Biden, who served under the nation's first black president, is the clear front-runner in South Carolina, with 35% support in the Real Clear Politics tally. Sen. Elizabeth Warren, D-Mass., comes in second with 15.5% support, and Sen. Bernie Sanders, I-Vt., carries 12.8%.

The Buttigieg campaign said that it has 40 full-time staff members and four offices in South Carolina.

Read the full text of the radio ad:

Woman's voice: Here's Democrat Pete Buttigieg:

Buttigieg: This country cannot afford four more years of Donald Trump.

We know that he is going to do everything he can to hold onto power. But if you nominate me, his playbook isn't going to work this time around.

I don't have to throw myself a military parade to see what a convoy looks like 'cause I was driving one around Afghanistan right about the time this president was taping Season 7 of The Celebrity Apprentice.

But I didn't just come here to end the era of Donald Trump, I am here to launch the era that must come next.

To do something about gun violence, to tackle systemic racism wherever we find it until your race in this country has no bearing on your health, or your wealth, your life expectancy or your relationship with law enforcement.

An American experience defined not by exclusion, but by belonging.

I am Pete Buttigieg and I approve this message. Paid for by Pete for America.