Republican senator says Trump diesel agreement with Russia may be illegal 

United States Senator Thom Tillis has questioned the legality of President Donald Trump’s decision to temporarily relax sanctions on Russian diesel, in an effort to bring down record-high fuel prices caused by the US-Israel war against Iran.

During a Sunday interview on the NBC News television show Meet the Press, Tillis argued that the sanctions relief could violate congressional law.

“I do believe there’s a legitimate case for saying the president’s not following the law,” said Tillis.

Trump’s decision has unsettled some Republican lawmakers who continue to support Ukraine in its war with Russia, which began in February 2022, after Moscow launched a full-scale invasion of the eastern European country.

Tillis warned that his vote in support of Trump’s legislative priorities would be contingent on the White House reversing course.

“If the president wants my support, which I believe he should get for funding military operations and year-end funding beyond baseline funding, I think the president needs to understand this is a problem, and I’m not the only Republican concerned with this,” Tillis said.

Tillis has become a critical voice within the Republican Party, denouncing what he sees as overreach from the Trump administration.

But his time as a senator is nearly at a close. In June 2025, Tillis announced he would not be seeking re-election in the November 3 midterm elections, after Trump threatened him with a primary challenge in his home state of North Carolina. His term ends in January.

Separately on Sunday, Tillis joined a bipartisan group of senators in issuing a letter to denounce the sanctions relief for Russia.

The group included Republicans like Susan Collins of Maine, Lisa Murkowski of Alaska and John Curtis of Utah, as well as Democrats Jeanne Shaheen and Richard Blumenthal.

“The United States should not provide [Russian President Vladimir] Putin with a financial lifeline while Russia continues to kill Ukrainian civilians. The Administration must immediately reverse course,” the senators wrote.

Another retiring Republican lawmaker, Representative Don Bacon, also said on Friday that “propping up Putin’s war economy is morally wrong as he uses that money to bomb cities”.

The pushback points to schisms within the Republican Party over Russia’s invasion.

Figures from the party’s establishment wing have generally pressed for robust support for Kyiv, while other party members have been sceptical of continued US support for Ukraine.

Trump himself has been critical of Ukrainian President Volodymyr Zelenskyy, accusing the government in Kyiv of impeding a US-negotiated ceasefire.

“I suggest they get a new leader who can make a deal, because he could have made many deals, and for some reason, he never does,” Trump said on Saturday. “That’s a war that should have never started, and I think it’s time for Ukraine to get a new president.”

A day earlier, Trump had announced that a call with Putin had concluded with an agreement to provide 300,000 tonnes of diesel to the global marketplace, with a further 500,000 tonnes to be delivered in November.

In an interview with Fox and Friends on Sunday, US Treasury Secretary Scott Bessent argued that the administration’s decision to ease some sanctions on Moscow was necessary to obtain relief from surging diesel prices.

“We’re going to do it with all the legal authorities we have,” Bessent said.

Analysts have said that the decision is unlikely to bring prices down in the long term. Critics like Tillis have also pointed to previous law barring the importation of Russian fuel, including a 2022 executive order.

A law signed last month — named after the late Republican Senator Lindsey Graham — also prohibits US investment in the Russian energy sector.

This year’s rise in global fuel prices has largely been attributed to the US-Israel war against Iran, which began in February. As a result of that war, Iran has limited commercial traffic through the Strait of Hormuz, a critical waterway for the fuel trade.

Tillis pointed to those circumstances in his remarks to Meet the Press.

“ If President Trump wants to end the strain on energy supplies, number one, get things right in Iran, and number two, recognise that it was Vladimir Putin, not Zelenskyy, that started this war,” Tillis said.

“It’s Vladimir Putin who owns the responsibility for energy prices to the extent that they come from that part of the world.”

Trump’s decision also garnered international criticism, with the office of Canadian Prime Minister Mark Carney issuing a statement in support of Ukraine.

“This agreement is in direct opposition to the efforts of Ukraine, Canada, and our allies to create peace and stability in Europe,” Carney’s office said in a read-out of a call on Sunday with Zelenskyy. “It will provide additional revenue for Russia and help finance its illegal, unjustifiable war against Ukraine.”