Vivek Ramaswamy confronted Sen. Joni Ernst over her criticism of his position on Israel at an Iowa political fundraising event last Friday, according to two sources who witnessed the tense exchange and video obtained exclusively by NBC News.

The two politicians ran into each other as Ernst, R-Iowa, was exiting a podcast studio at Rep. Mariannette Miller-Meeks’ “Triple MMM Tailgate” fundraiser and Ramaswamy was heading in. Ramaswamy shook Ernst’s hand and held onto it for most of a minute as he aired his frustration.

“You might want to understand my Israel policy before commenting,” said Ramaswamy, who was upset about Ernst’s remarks at a panel discussion on foreign policy in New Hampshire a week earlier.

As both smiled through their tough talk, Ernst said: “I’d be glad to talk to you, because I heard you had some perspectives. So I was asking, what is your policy?”

Ramaswamy, a political newcomer who is seeking the GOP presidential nomination, has come under heavy fire from fellow Republicans for an interview he did with conservative pundit Tucker Carlson this month that touched on America’s interest in the war between Israel and Hamas.

The private interaction illustrated some of the pushback Ramaswamy has been receiving — and how he’s working to overcome it as the conflict has become a key issue splintering the party ahead of a conference with Republican Jewish voters and the third primary debate.

“The selective nature of ignoring certain other conflicts — while even more importantly ignoring the interests of the U.S. right here at home — is what irritates the heck out of me, out of the politicians in both parties,” Ramaswamy said in the interview with Carlson on X. “It is shameful, and I think that there are, frankly, financial and corrupting influences that lead them exactly to speak the way they do. That’s just the hard truth.”

Many Republicans reacted with outrage at Ramaswamy for what they perceived to be the conjuring of an old trope about Jewish power, aggravating long-standing wariness that some in the GOP have about his policies on Israel.

At a Bastion Institute forum in New Hampshire on Oct. 13, Ramaswamy rival Doug Burgum blasted him for suggesting American supporters of Israel are “bought and paid for.”

Ernst, sitting next to Burgum onstage, let out a whoop of approval and thanked him several times.

“Having people running for high elected office here in the United States shifting the blame away and saying it’s all about fundraising, it’s abhorrent,” Ernst said, clearly alluding to Ramaswamy. “We need to stand with our friends, Israel.”

In Iowa last week, as they continued their long handshake, Ramaswamy bored into Ernst about her participation in talks about the prospect of Saudi Arabia’s developing civil nuclear energy as part of a broader pact with Israel.

The U.S. should “deeply rethink” allowing Saudi Arabia to have “nuclear capabilities outside of … a normalized U.S. civilian nuclear transfer,” Ramaswamy said.

Ernst, who led a congressional delegation to Saudi Arabia and who had just met with the prime minister, Crown Prince Mohammed bin Salman, when Hamas struck Israel on Oct. 7, replied that any Saudi civil nuclear program would be overseen by a U.S. entity.

Ramaswamy, who is polling fourth nationally in the RealClearPolitics average of several GOP primary surveys, moved back to the topic of the war in the Middle East.

“The most pro-Israel thing we could do right now is to debate what is actually happening before we get into another Iraq or Afghanistan,” he said. “So that’s where I’m at.”

Ernst responded that she is not “fully supportive of a ground invasion,” either.

Ramaswamy said he had heard, “maybe secondhand, some of the comments in New Hampshire, I think relating to your awareness of my Israel policies.”

Then, he was beckoned to join the podcast.

“But anyway,” Ernst said as they shook hands again, “don’t make assumptions about where I am [on policy], either.”

Ramaswamy retorted one last time: “And vice versa.”

A top aide said Ramaswamy believed the U.S.-mediated negotiations between Saudi Arabia and Israel were most likely a factor in the Oct. 7 terrorist assault on Israel.

“The idea of the U.S. transferring nuclear technology to Saudi Arabia this year is absolute lunacy — and almost surely played a role in catalyzing the recent attack on Israel,” said Tricia McLaughlin, the Ramaswamy aide. “You can’t simply parrot slogans like ‘We stand with Israel’ while explicitly advancing policies that catalyzed the attacks on Israel without acknowledgment of that reality.”

The unusually frank confrontation with Ernst reflects Ramaswamy’s approach to politics, McLaughlin said.

“Unlike career politicians, Vivek prefers to … debate those who disagree with him directly, rather than to do it like a coward behind their backs,” she said.

Ernst, whose delegation traveled to Israel on Oct. 10 for meetings with Prime Minister Benjamin Netanyahu and other Israeli officials, served in Iraq and Kuwait in the Iowa National Guard during the Iraq War.

Her spokeswoman, Kelsi Daniell, said there was little need to elaborate on the exchange.

“Retired Lt. Col. Ernst’s words in the video speak for themselves,” Daniell said in a text message.

Ramaswamy’s stance on Israel has been the subject of intense scrutiny on the right since long before Hamas launched its terrorist attack this month. During the first GOP presidential debate in August, former United Nations Ambassador Nikki Haley, a staunch supporter of Israel, lambasted Ramaswamy’s call to cut off aid to the country after 2028. Ramaswamy had said such aid would no longer be necessary by then, because he pledged to negotiate “Abraham Accords 2.0” with the aim of fully incorporating Israel with its Middle Eastern neighbors.

“You have no foreign policy experience, and it shows,” Haley said of Ramaswamy in a viral moment from the Milwaukee debate.

Now, Ramaswamy, who is cautioning the U.S. against getting involved in a potential broader war in the region, called on lawmakers to reject President Joe Biden’s proposed aid package of more than $100 billion for Israel and Ukraine and said aid to Israel should be “contingent” on the country’s providing clear objectives for its military effort.

“‘Destroy Hamas’ is not on its own a viable or coherent strategy,” he said in a statement.

He has said, though, that the U.S. should provide the Israelis with intelligence and diplomatic support, as well as weapons for sale or transfer. In a lengthy tweet promoting the interview with Carlson, Ramaswamy called the Hamas-led attacks, during which roughly 1,400 people were killed and more than 200 were taken hostage, “barbaric,” adding they “cannot be condoned.”

“We require a rational response that supports Israel while avoiding another U.S.-led disaster in the Middle East,” he said.

After the interview, Ramaswamy published a statement forcefully pushing back against the idea that he was promoting an antisemitic trope about the influence of Jewish funding when he discussed the impact of “financial and corrupting influences” on his rivals’ positions on Israel policy.

“There’s plenty of actual anti-Semitism in the world, as has been made painfully clear with Hamas’ murderous assault on Jews and the reaction by their apologists, whether it’s BLM chapters or Harvard student groups,” he said. “Anti-Semitism is morally outrageous, and it’s wrong to artificially manufacture more of it.”

Ramaswamy will no doubt have to address his position on Israel more in the coming days when he speaks with Jewish voters Saturday morning at the Republican Jewish Coalition conference in Las Vegas.