(CNN) When a bipartisan group of lawmakers visited the Ukraine border in March, an unexpected guest showed up on the trip: GOP Rep. Victoria Spartz of Indiana.
Spartz, the first Ukrainian-born member of the US Congress and an outspoken advocate for her home country, had expressed interest in joining the congressional delegation but wasn't invited to attend the trip, which consisted primarily of House Foreign Affairs Committee members, a panel where Spartz is not a member.
So, she used her own funds to fly to the border of Ukraine in Poland and linked up with lawmakers once there to join in on some of their meetings, according to multiple sources familiar with the situation.
Her surprise appearance, the circumstances of which have not been previously reported, was initially viewed as a welcome addition -- albeit an unusual one -- as lawmakers sought to rally Western support for Ukraine amid Russia's bloody assault on the country that began a week earlier.
But members who were part of the official trip told CNN that Spartz was "argumentative," "accusatory," and "unhelpful" during key meetings with NATO members, generals and government officials, sparking concern that her presence was doing more harm than good.
"She crashed our CoDel. She was like a bull in a china shop," said one GOP lawmaker, who like other members for this story was granted anonymity to speak more freely about a colleague and due to the sensitive nature of the subject. "I don't know if it was pent-up frustration or she didn't feel like she was getting enough proper information, but she was just accusatory and rude."
Spartz, in an email to CNN, pushed back on the anonymous criticism of her decision to elbow her way into the congressional delegation and refuted the description of her behavior on the trip.
"This accusation is a cowardly misrepresentation of facts by some jealous members or staff since we had a very productive bipartisan CODEL in March," Spartz said. "I did not come to Congress to get paid for my travel vacations or dinners, but rather get things done. I have always been willing to spend my own hard-earned money to help with causes I care about."
That bipartisan frustration over Spartz's behavior was only the beginning. In the nearly six months since the war began, Spartz has publicly criticized the Ukraine government, peddled corruption allegations against the Ukrainian government and some of Ukrainian President Volodymyr Zelensky's top aides, and spurred complaints from her colleagues that she is mirroring pro-Russia talking points.
"President Zelensky has to stop playing politics and theater, and start governing to better support his military and local governments," Spartz said in a press release last month, in one example of her outspoken criticisms of Kyiv.
Spartz, a 43-year-old businesswoman, has repeatedly insisted, publicly and privately, that she wants Ukraine to win, and that she is only attacking Kyiv because she wants to help remove any potential obstacles to a Ukrainian victory over Russia. She says she has visited Ukraine six times since the invasion began and has also slammed Russia consistently, including as recently as Tuesday when she tweeted that Russia should be declared a terrorist state.
Still, Spartz's bellicose rhetoric aimed at Zelensky and his advisers has frustrated lawmakers in both parties, White House officials and members of the Ukrainian parliament alike. They worry she is undermining their efforts to stay united behind Ukraine at a pivotal moment and openly question where she is getting some of her information, according to interviews with over a dozen lawmakers, aides and administration sources.
Meanwhile, multiple briefings from the Biden administration and private pleas from senior Republicans have done little to rein in Spartz's vocal criticism, sources said.
Once seen as a crucial messaging asset, Spartz has now become something of a liability for defense hawks who were already worried about fatigue in the United States over the ongoing war abroad. And her continued criticism of Ukraine also comes amid growing skepticism from the MAGA wing of the GOP about keeping weapons and aid flowing to the country.
"Because she's the only Ukrainian-born member of Congress, she has outsize megaphone, outsize influence," Rep. Elissa Slotkin, a Michigan Democrat and former CIA analyst, said to CNN. "I think there's an open question of why she's so openly saying something that's so clearly aligned with Russian talking points."
Spartz contends she has long been concerned about corruption in Ukraine. But lawmakers fear her public criticism could undermine confidence in Zelensky, damage relations between the U.S. and Ukraine, and give on-the-fence lawmakers a reason to oppose the next aid package.
Some lawmakers -- even those unhappy with her rhetoric -- came to Spartz's defense, arguing she is well-intentioned and just desperate to help her motherland as it's being ripped apart by war. Spartz was a vocal champion of key legislation to speed up the administration's ability to send weaponry and other critical resources to Ukraine, attending the bill signing ceremony with President Joe Biden. And lawmakers in both parties have shared in her calls for more rigorous oversight of the weapons heading into Ukraine.
"She was overcome with emotion. And I think what you're seeing now is a manifestation of that," said a second GOP lawmaker. "What I'm trying to tell her is, I'm well aware of the corruption problem. ... But talking about corruption now, when they are under siege, is like wall-papering your bathroom when the house is burning down around you. It's counterproductive."
Spartz said in an email to CNN that she is just seeking accountability and always gets her information "from the ground and real professionals, not from academics and political hacks who've never set foot in Ukraine." And Spartz said it was the "foreign policy establishment" -- not her -- who was playing into Russian President Vladimir Putin's hands.
"I also care deeply about people's lives -- the lives of ordinary Ukrainians and the brave Ukrainian military. I cannot let them down even if that means saying unpopular truths that offend the politicians or diverge from the popular narrative of the day," Spartz said. "I will never give up or give in, and I will do everything I can to see a united Ukraine and a defeated Vladimir Putin."
Even as lawmakers express understanding and sympathy for Spartz's situation, the top three Republicans on the House Foreign Affairs Committee, the House Intelligence Committee and the House Armed Services Committee have all urged Spartz to tone down her posture, according to multiple sources familiar with the situation.
"We've all talked to her," said a third GOP lawmaker. "It's pissing people off. Because it hurts the cause."
Spartz herself has expressed interest in joining the House Foreign Affairs Committee next year, sources said. But given her recent behavior, some GOP members have warned Republican leaders against that, with one lawmaker saying they would be "very upset" if she received that assignment.
When asked about the pushback she's gotten from top Republican colleagues surrounding her rhetoric and whether it's playing into Russian disinformation campaigns, Spartz responded: "not true."
"Republican leadership has been supportive and appreciate my demands for accountability and a real strategy for the war effort in Ukraine," she said.
Spartz also admonished her colleagues for making anonymous claims about her interest in the House Foreign Affairs Committee. "A lot of members of Congress behave immaturely and are deeply unserious dealing with very serious issues," she said.
The Biden administration has also gotten involved. Spartz recently received a nearly two-hour briefing from officials from the National Security Council and State Department after requesting one from the White House about Ukraine, sources familiar with the meeting told CNN, where the officials walked through her claims of improper behavior inside the Ukrainian government and either refuted the allegations or said there was not enough evidence to support them.
Spartz also requested a meeting with Joint Chiefs Chairman Gen. Mark Milley to discuss her concerns, the sources said. The meeting was first reported by Politico. When they met, she again raised concerns about corruption in Ukraine and alleged that US-provided weapons were not going to the right places.
Milley did not dismiss her concerns outright, the sources said -- US officials believe corruption continues to be a problem in Ukraine. In a recent call with Ukrainian counterparts, Milley, National Security Adviser Jake Sullivan and Secretary of State Antony Blinken discussed "the importance of Ukraine continuing to implement its reform agenda" with regard to corruption, "despite the challenges caused by the war," according to a readout provided by the White House.
Broadly, however, Milley explained to Spartz that her concerns were overwrought, the sources explained.
Spartz told CNN that her meeting with Milley "was not my first meeting with him," and that "I give him credit for his willingness to listen."
"I believe he understands the challenges of our effort in Ukraine, but the politicians and foreign policy establishment are making strategic decisions, not military leaders," she said. "This should trouble all Americans as these are the know-nothing know-it-alls who oversaw the debacle in Afghanistan, and other foreign policy blunders, and have faced zero accountability."
Several days after meeting with Milley, Spartz continued her public attacks on one of Zelensky's top aides, accusing him of "creating a per se dictatorship under the disguise of the ongoing war."
House Minority Leader Kevin McCarthy told CNN he has not privately spoken to Spartz about her criticism of the Ukraine government. But he did credit the Indiana lawmaker for being passionate about the issue and helping to draw attention to the war -- especially in the early days of the conflict, when Spartz delivered an emotional public plea to the Biden administration for a concrete Ukraine strategy during a GOP press conference that garnered widespread media coverage.
"The thing you've got to understand: she's got family there, she's very passionate about it," McCarthy said. "It's very personal."
There is also concern about Spartz's behavior abroad. Slotkin said Spartz came up in multiple meetings and dinners when she was recently in Kyiv and that last week she received a text message from a member of the Ukrainian parliament saying they don't know if Spartz is being "played" but "she has ruined her reputation in Ukraine."
"All the senior leaders were talking about it. They're upset about it," Slotkin said. "They don't understand why she's doing this."
Ukrainian officials have become increasingly alarmed by Spartz's rhetoric over the last several months, Ukrainian sources told CNN, particularly her persistent attacks on Zelensky's powerful chief of staff Andriy Yermak. In tweets last month, she accused Yermak of "undemocratic governance" and said he had a "negative reputation" globally. And on July 8, Spartz sent a letter to Biden requesting a briefing specifically about Yermak "and his alleged dealings in connection with Russia."
Spartz's accusations are similar to those reported by Radio Free Europe before the war, which alleged Yermak had business ties to Russia. That allegation has been used by Zelensky's critics to suggest Yermak might be too willing to bend to Kremlin demands, particularly following a controversial prisoner swap deal in 2021. There is no evidence that he is under the Kremlin's sway, however, and he has denied the allegations.
Ukrainian officials have questioned Spartz's motivations. In text messages to a Zelensky aide on June 24, Spartz offered to "connect" the aide "with the right people" who she said could help Ukraine's army win.
"Do you want me to send someone good to discuss training when you are back or maybe he could meet with Reznyk or someone else this coming week?" Spartz asked, referring to Ukrainian Defense Minister Oleksii Reznikov. "Some of them can also bring some very advanced equipment for you to use ... he will do it as a favor for you and for me so we will have to keep these meetings 'off the record,'" Spartz wrote.
Asked about these texts, Spartz told CNN they were taken out of context and that she has "simply been trying to help make connections for anyone willing to help Ukraine win the war especially to some veterans who can give free and unbiased advice as a favor to me since they are my friends." She added that "the insinuation I have some financial interest is flatly untrue; I'm spending tens of thousands of my own money to help in Ukraine. Mr. Yermak's financial interests are what merits investigation."
Ukrainian officials have offered to set up a meeting between Yermak and Spartz to clear the air, but Spartz has declined to take it, sources said. Spartz acknowledged that she was offered a meeting with Yermak after she sent the letter to Biden, but then the Ukrainian Foreign Ministry criticized her attacks on Yermak as "cynical" and "baseless."
"I determined this meeting would not be productive under those circumstances," she said.