President Donald Trump wants to buy diesel from Russia to bring down fuel prices for American drivers. But can a deal with Vladimir Putin fix an energy crunch when Russia is still bombing Ukraine, Congress has already restricted Russian fuel, and the biggest disruption to global supplies is unfolding thousands of miles away? That is a great deal for one agreement to solve.

The political stakes are rising quickly. The US midterm elections arrive next month, and climbing energy prices are eroding Trump's position. The reach of those prices extends past the gas pump: diesel powers the trucks, trains, and farm machinery that move food and goods, so fuel costs land on businesses and households alike. The Trump administration has temporarily waived sanctions on Russian diesel in a bid to ease the squeeze at the pump, a shift that opens the way for outcomes that could include the US government effectively sending money to Russia even as its army continues attack Ukraine.

The diesel deal runs into a problem called US law

Republican Senator Thom Tillis is among the lawmakers questioning whether Trump can legally reopen the trade. His concerns reflect a broader unease among Republicans. On NBC's Meet the Press on Sunday, Tillis directly challenged the president's authority.

"I do believe there's a legitimate case for saying the president's not following the law," Tillis said.

A 2022 executive order, issued in response to Russia's full-scale invasion of Ukraine, blocked imports of Russian energy products. A separate law signed last month, named for the late Republican Senator Lindsey Graham, prohibits American investment in Russia's energy sector. A sanctions waiver cannot automatically erase either restriction. Together, the measures form a legal wall around Russia's energy sector that a waiver alone cannot dismantle.

"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. The linkage matters in practical terms, since the funding measures he cites need congressional approval to pass.

Other senators demanded a full reversal, warning against American money flowing to Russia while civilians die under Russian bombardment. Retiring Republican Representative Don Bacon voiced his objection to the plan on Friday.

"Propping up Putin's war economy is morally wrong as he uses that money to bomb cities," Bacon said.

Senator John Barrasso struck a more measured view, saying Trump is trying to reduce energy costs while navigating international tensions. Barrasso argued that the president could also use pressure on Moscow to negotiate a longer-term settlement, although he urged the administration to enforce the sanctions Congress passed just last month.

"The president is balancing and has to make tough decisions," Barrasso said on CBS's Face the Nation. "We're going to do it with all the legal authorities we have."

Russia is hardly making the ceasefire pitch easier

The economic rationale is flawed as well, because analysts do not foresee Russian diesel producing an enduring decrease in prices. Much of this year's fuel crisis resulted from the Israel-US attack on Iran that began in February. Iran then curbed traffic through the Strait of Hormuz, a channel critical to global energy shipments.

Against that backdrop, Trump announced an energy ceasefire over the weekend, claiming Ukraine and Russia had agreed to stop striking each other's power and fuel infrastructure. Neither side independently confirmed that any such agreement existed. It was his second unconfirmed ceasefire announcement in weeks.

By Monday, Ukrainian President Volodymyr Zelenskiy was describing a very different reality. Russian attacks overnight and into the morning struck at least six energy-related sites across Ukraine, with deaths reported, according to the Ukrainian leader. Speaking at a conference in Poland, he identified a gas facility and a gas station among the sites hit by drones.

"It is increasingly evident that Russia is unwilling to accept an energy ceasefire proposed by the United States and intends to continue its terrorist air attacks against our people and communities," Zelenskiy wrote on X. "This is what happens when Russia sees the prospect of higher revenues for its war machine."

Zelenskiy has condemned the diesel arrangement as a retreat from years of Western efforts to isolate the Russian economy. Trump, meanwhile, has escalated the already strained relationship between the two leaders by publicly calling on Ukrainians to elect a different president.

"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.

Ukraine's European allies, meanwhile, have openly questioned whether any ceasefire agreement actually exists. On Monday, they sided firmly with Kyiv and approved the European Union's largest new package of sanctions against Russia since the full-scale invasion began in 2022.

Tillis, for his part, argued that the White House is searching for an answer in the wrong country entirely. Resolving the crisis, he said, requires addressing Iran's shipping restrictions and acknowledging who started the war in Ukraine.

"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.