Prices for diesel, used for agriculture, heating homes and trucking, are near a record and risk for Trump's fellow Republicans ahead of the November 3 congressional elections that will determine whether they maintain thin control of Congress.
Diesel prices fell after the announcement, but analysts said the deal may not be enough to keep them down.
Trump said on social media he had a "highly successful" discussion with President Vladimir Putin in which they agreed that Russia will immediately supply more than 300,000 metric tons of diesel to US and global markets, equal to about 2.25 million barrels of fuel.
The US exports about 1.5 million barrels of diesel per day.
After the call, an envoy for Putin, Kirill Dmitriev, praised co-operation between Russia and the US in a post on X.
Dmitriev asked US officials during his visit to Washington in September for licenses to export diesel to the US market to be granted to all Russian major oil firms, sources familiar with the situation said.
In October 2025, the US imposed sanctions on Russian oil companies over Moscow's war that began in 2022. The diesel exports could provide Moscow with billions of dollars in revenues that could help Putin continue the war with Ukraine.
Ukrainian President Volodymyr Zelenskiy criticised the deal, announced while a Ukrainian delegation was in the US to discuss how to seek a resolution of the war, as a "weak decision on the part of strong partners".
"Gifts to Putin will not bring peace or any benefit to the civilized world. Russia will 'repay' the diesel with further terror and perfidy," he said on X.
The deal was also criticised by US lawmakers including Trump's fellow Republican, Representative Don Bacon, who said it was time to apply more sanctions Congress passed recently, not lift the measures.
"Now is the time to use those sanctions to squeeze Putin's war machine, not reward a dictator by putting more money in his hands while he continues targeting and killing Ukrainian civilians," Bacon said on X.
The US Treasury Department issued a licence allowing importation of Russian diesel until April 7.
Trump said Russia would supply another 500,000 tons in November and a further 1 million tons "immediately thereafter".
Even more would follow, Trump said, "based on the condition of their diesel refineries", which have been damaged by Ukrainian attacks.
Analysts said the agreement was unlikely to lead to sustained lower fuel prices.
"I cannot overstate how much of a nothing burger this is," Rory Johnston, an oil market researcher and founder of CommodityContext.com, said on X, adding that Russia usually exports much more diesel than volumes in the deal when its refinery fleet is not under attack.
Diesel prices, which are often a big driver of inflation, are up 70 per cent since the US and Israel launched the war with Iran on February 28.
The wars in Iran and Ukraine have triggered a severe global fuel supply crunch, pushing average US diesel prices to $US6.28 ($A8.99) a gallon on Thursday, according to the AAA motorist group.
Prices have stayed high despite two recent moves by Trump to boost supplies of the fuel: pressuring allies to release emergency reserves and expanding access to tax-exempt red-dyed diesel, which is normally used for farm equipment.
