Democratic presidential hopeful Pete ButtigiegPeter (Pete) Paul Buttigieg2020 presidential candidates slam Trump over withdrawal from Paris climate deal Overnight Health Care: GOP Georgia governor proposes limited Medicaid expansion | Sanders calls his 'Medicare for All' plan 'more progressive' than Warren's | Oklahoma Supreme Court blocks law targeting abortion procedure Krystal Ball rips 'utterly embarrassing' CNN report comparing Buttigieg to Obama MORE's campaign on Tuesday released a TV ad in Iowa highlighting national unity as he rises in state and national polls. 

The ad, which is Buttigieg's sixth in the state, includes excerpts from his speech at last week's Liberty and Justice Celebration in Des Moines. 

"The point is what lies on the other side of the fight," the South Bend, Ind., mayor said in the speech. "The hope of an American experience defined not by exclusion but by belonging. That is what we are here to deliver."

Buttigieg has risen from the middle of the Democratic primary's field to fourth place, trailing former Vice President Joe BidenJoe BidenRand Paul demands media print whistleblower's name Kentucky rally crowd behind Trump all wear 'Read the Transcript' shirts 2020 presidential candidates slam Trump over withdrawal from Paris climate deal MORE and Sens. Elizabeth WarrenElizabeth Ann WarrenOvernight Health Care: GOP Georgia governor proposes limited Medicaid expansion | Sanders calls his 'Medicare for All' plan 'more progressive' than Warren's | Oklahoma Supreme Court blocks law targeting abortion procedure On The Money: Dow hits record high | Optimism on trade deal lifts markets | Appeals court upholds NY prosecutors' subpoena for Trump tax return Krystal Ball rips 'utterly embarrassing' CNN report comparing Buttigieg to Obama MORE (D-Mass.) and Bernie SandersBernie Sanders2020 presidential candidates slam Trump over withdrawal from Paris climate deal Overnight Health Care: GOP Georgia governor proposes limited Medicaid expansion | Sanders calls his 'Medicare for All' plan 'more progressive' than Warren's | Oklahoma Supreme Court blocks law targeting abortion procedure On The Money: Dow hits record high | Optimism on trade deal lifts markets | Appeals court upholds NY prosecutors' subpoena for Trump tax return MORE (I-Vt.). 

A New York Times-Siena College survey released last week showed Warren leading the field in the Hawkeye State with the support of 22 percent of respondents, followed by Sanders at 19 percent and Buttigieg and Biden at 18 and 17 percent, respectively. 

Meanwhile, Buttigieg made gains in a Washington Post-ABC News poll released on Sunday, but still trails Biden, Warren and Sanders nationally. 

Buttigieg made headlines over the weekend when he suggested that the Democratic primary could turn into a two-way race between him and Warren. 

He later walked back the remarks, however, saying he did not think the comments came out right before emphasizing the strength of the other contenders in the race.