KEY POINTS Biden told Iowa voter to "vote for someone else" after being questioned about climate change

In a video, Biden can also be seen grabbing the man's jacket and poking him

The man said the exchange was "shocking"

With Iowa set to make their choice for the Democratic presidential nominee in less than a week, the candidates that can are busy holding campaign events in the state. Former Vice President Joe Biden is no exception – but after a strange, tense exchange with one voter, his campaign may need to perform some damage control.

At a small event campaign hosted by Biden’s campaign in Des Moines, the former vice president was approached by Ed Fallon, the leader of the environmental conservationist group Bold Iowa. When Fallon spoke to Biden, Fallon explained that he would support Biden if he ends up as the Democratic nominee, but expressed concern about the candidate’s policies on climate change and specifically oil pipelines.

In a response Fallon described as “shocking,” Biden told him to “go vote for someone else,” implying that he supports Sen. Bernie Sanders, I-Vt. At one point, Biden grabbed Fallon by his jacket lapels and said: “I’m running in the primary.” Biden also poked Fallon in the chest during their conversation.

In addition to being the head of Bold Iowa, in the past, Fallon has served in Iowa’s general assembly. He said that although he’ll back Biden in the general election, Tom Steyer is his first choice. Fallon told The Independent that he’s repeatedly approached Biden about his concerns around climate change and fossil fuels, but “it’s never been resolved. It seems like there’s a disconnect,” Fallon said.

Writing on the Bold Iowa website, Fallon said that he found Biden’s behavior during their talk to be “disturbing on a number of levels,” citing his “propensity to violate personal space” as creating “prime fodder for opponents and the media” to attack Biden’s campaign.

More importantly, Fallon wrote, “Biden is simply wrong on climate change and out-of-step-with voters on so many issues.”

Businessman and presidential hopeful Tom Steyer addressed the confrontation on Twitter, writing that “this is no way to treat an Iowan.”

Biden has faced criticism during his campaign for his sometimes terse interactions with voters. In one instance, when confronted about the allegations that he and his son, Hunter Biden, had engaged in misconduct in Ukraine, responded by calling the man a “damn liar” before challenging him to a push-up contest.