President Trump said on Friday that Russia would ship millions of tons of diesel to American and world markets, announcing the deal after a phone call with President Vladimir Putin of Russia.

Russia will “immediately supply over 300,000 tons of diesel fuel to the American and global marketplace, another 500,000 tons during the month of November, and 1,000,000 tons immediately thereafter,” Mr. Trump wrote on Truth Social, as Al Jazeera reported. He said another 3 million tons would follow “within a short period of time,” depending on “the condition of their Diesel Refineries.” That comes to more than 4 million tons, CNBC reported.

The Treasury Department issued a general license within hours. It allows Russian diesel to be sold, delivered and imported until April 7, 2027, according to the license, and covers fuel loaded onto tankers as of Friday. The department eased Russian fuel sanctions in March and April too, though Treasury Secretary Scott Bessent had ruled that out earlier in the year. Those waivers ran the standard 30 days. This is the first diesel license to run longer since Russia invaded Ukraine in February 2022, CBC reported.

Last month Mr. Trump signed a sanctions law named for the late Senator Lindsey Graham. It targets Russian officials, banks and a shadow fleet of tankers, and it directs the president to put tariffs of up to 100 percent on the top five importers of Russian oil or gas. The diesel deal casts doubt on whether the White House will impose sanctions this month.

President Volodymyr Zelensky of Ukraine called it “a weak decision, unfortunately, a weak decision by strong partners,” in a statement released by the Ukrainian Embassy in Washington. “Gifts to Putin will not bring peace or any benefit to the civilized world,” he wrote online. “Russia will ‘repay’ the diesel with further terror and perfidy.”

The timing stung. Mr. Trump made the announcement as a Ukrainian delegation met his envoy Steve Witkoff and son-in-law Jared Kushner in Miami to discuss a proposal to end the war. “I believe our team is simply being used as a smokescreen,” Mr. Zelensky said. On Thursday, a Russian strike on a bus stop in eastern Ukraine killed more than 30 people, CNN reported.

In a Kremlin statement, Mr. Putin said Russia “confirmed its readiness to supply oil and petroleum products to the American and global markets” and added, “I am confident this will have a positive impact on the entire global economy.” His aide Yuri Ushakov wouldn’t say whether the United States had promised anything in return. The White House did not immediately answer questions about who would pay for the diesel or when it would arrive.

“I want to thank President Putin,” Mr. Trump told reporters as he left for a campaign rally. He did not answer shouted questions about Mr. Zelensky.

Diesel averaged $6.28 a gallon on Friday, up from $5.94 a month earlier and $3.68 a year ago, according to AAA figures cited by CBS News. The record, set Sept. 22, was $6.53, by CBS’s count, and $6.52 by CBC’s. Diesel futures closed down about 4 percent.

Analysts doubted the deal would hold prices there. The first two shipments together equal about six million barrels, roughly a day and a half of U.S. demand, according to the Energy Information Administration. “There is a reason Trump talked about volumes in tons instead of barrels,” Dan Pickering, chief investment officer at Pickering Energy Partners, said in an email. “The tons number looks bigger to a general observer.”

Russia banned diesel exports in early July after Ukrainian drones hit its refineries, pulling roughly 800,000 barrels a day off a market already squeezed by the U.S. war with Iran. It extended the ban last month. Clayton Seigle of the Center for Strategic and International Studies said the deal would do “probably not much” for prices but was a “great benefit to Russia and to Putin.”

Senate Democratic leaders said Mr. Trump was “selling out Ukraine and our allies in a desperate attempt to save Trump’s political prospects” before the Nov. 3 midterms. Senator Richard Blumenthal, a Connecticut Democrat who co-sponsored the sanctions law, called the agreement “a stain on our nation’s character” and “an insult to Lindsey Graham’s memory.”

“How does anyone take the sanctions regime seriously?” said Richard Nephew, a former State Department sanctions official.

Mr. Trump signed an executive order this week letting truckers run red-dyed diesel, which is exempt from the 24.4-cent federal tax, on highways. That order only defers the tax, CNBC reported.

Gregory Brew, an analyst at Eurasia Group, said in an email that he suspected Mr. Putin expected Ukraine to stop hitting refineries in return. “I have a hard time seeing Zelensky cooperate on that front,” he said.