DES MOINES, Iowa — Pete Buttigieg tried to stress the importance of being respectful despite a difference in opinions after demonstrators protesting his record on helping homeless veterans disrupted a town hall.

"Can I hear it one more time for the idea of respectful, honest, open, and transparent dialogue?" Buttigieg said Sunday in Des Moines, Iowa.

Buttigieg, a top-four contender for the 2020 Democratic presidential nomination, had just slammed President Trump's handling of escalating tensions with Iran, saying he was risking the lives of U.S. troops who could be deployed to the region for an avoidable war.

"We've been trying to talk to you," one demonstrator said in response to the mayor's attempts to placate them.

Buttigieg supporters drowned out the shouts of the two main protesters by chanting the former mayor's name before activists started a competing, "Black Lives Matter," chant.

Buttigieg spokesman Sean Savett defended the candidate's record as chief executive of South Bend, Indiana. Savett said homelessness decreased by 33% over Buttigieg's two terms, adding he joined a national effort "to eradicate veteran homelessness by connecting homeless veterans with housing and other services, and achieved 'functional zero.'"

Buttigieg was similarly heckled this week during his California swing. Protesters told the Los Angeles Times, their travel from South Bend to the West Coast was paid for by a third party, but wouldn't disclose the identity of their financial backer.