A handful of Republicans have spoken out against Donald Trump’s softening stance on Russia, threatening to pull financial support for his agenda over his “embarrassing” handling of the Ukraine war.

Don Bacon, an outgoing congressman in Nebraska, condemned Trump’s actions – which include a stunning agreement to buy Russian diesel and the pausing of sanctions on Moscow – as “absolutely disgraceful” and accused the US president of cozying up to a “war criminal” in Vladimir Putin, his Russian counterpart.

“It really is disgraceful, and the Republicans that I associate with, there’s a lot of us, can’t stand it,” Bacon told CNN on Monday. “I think the president’s leverage in this Congress is shot.”

Last week, Trump waived sanctions imposed on Russia through a law named after his longtime ally and late senator Lindsey Graham. The legislation, which he signed only last month, was intended to increase financial pressure on Russia, more than four years after it invaded Ukraine.

Instead, Trump announced he had struck a deal with Putin to import diesel fuel, which has become more expensive for Americans largely due to Trump’s war with Iran. Trump has previously blamed Ukraine’s strikes on Russia.

Over the weekend, Trump claimed Zelenskyy “doesn’t care” about the impact of Ukraine’s strikes on Russia and “doesn’t want to end this war and probably never did” because Ukraine is receiving financial support from Europe.

Trump also suggested Zelenskyy should step down on Monday, saying it was “time for somebody else to negotiate on behalf of Ukraine”.

In an interview with Bloomberg, Ukraine’s president, Volodymyr Zelenskyy, said he believed Trump was taking steps to “convince Ukraine to capitulate” to Russian demands. On social media, Zelenskyy reaffirmed Ukraine’s partnership with the US.

Darline Graham, the sister of Lindsey Graham and now a senator from South Carolina, broke with the president on his decision over the weekend, telling reporters on Saturday: “Personally, I would choose to put the pressure on Russia to end the war and get gas prices down because I don’t trust Putin, and I don’t trust Russia.”

“[Ronald Reagan] and [Lindsey Graham] would be ashamed of this,” Bill Cassidy, the outgoing US senator from Louisiana, wrote on X in response to a recent Wall Street Journal editorial on the matter.

Mitt Romney, a former Republican senator and presidential candidate, wrote on social media that if the US abandoned Ukraine, it would also “abandon liberty”.

Some lawmakers had already raised concerns about the president’s support for Ukraine after Ukrainian officials said the country’s access to Starlink, a satellite internet service powered by Elon Musk’s company, was restricted last week. Musk hinted on social media that the US government controlled Ukraine’s access.

Zelenskyy also accused the US government of withholding intelligence about an incoming Russian missile attack on Sunday evening – the third accusation of its kind.

Brian Fitzpatrick, a Pennsylvania congressman, told MS Now on Monday that the Trump administration had not given “sufficient answers” about the recent disruptions to Starlink and the diesel deal.

“This is wildly unacceptable, and it’s not going to stand,” Fitzpatrick said. “There’s going to be consequences to this. And by the way, it’s not just Starshield. It’s the diesel deal. It’s the lifting of sanctions. It’s all of this stuff.”

Fitzpatrick said lawmakers would “demand accountability” and that they could take “punitive budgetary action” to force the administration to provide answers.

Bacon told CNN he was unwilling to support the president’s agenda, such as building a triumphal arch or a new White House ballroom, while he withheld support for Ukraine.

“Why would I want to support the president’s priorities, like the victory arch?” Bacon asked. “Frankly, what I see him doing here is surrendering.”

Bacon added: “Why should we try to accommodate him and meet him halfway on funding when he is embarrassing this country so bad with what he’s doing with Putin and Zelensky?”