President Donald Trump said on Sunday that Russia and Ukraine had agreed to an immediate "energy ceasefire," an announcement that appeared to catch Kyiv by surprise and came just two days after he unveiled a deal for Russia to supply the United States with diesel.

The sequence underscores how quickly Washington's posture toward Moscow's energy flows has shifted: in the space of a weekend, the United States moved from sanctioning Russian energy to buying it, and then declared a truce over it.

Trump announced the truce in a social media post, saying both sides had agreed and warning them not to break it. A Ukrainian official told CNN that Ky had learned of the agreement the same way the public had — by reading the post. Neither the White House nor the Kremlin has explained how the agreement was reached or what it covers.

Ukrainian President Volodymyr Zelensky said Ukraine supported the ceasefire, that Russia needed to do the same, and that Kyiv was awaiting details from Washington. He said he had discussed the news with Canadian Prime Minister Mark Carney, Finnish President Alexander Stubb and NATO Secretary General Mark Rutte.

Earlier on Sunday, Zelensky told ABC News that Ukraine would stop attacking Russian diesel facilities if Russia halted its attacks, describing that as a fair trade. Ukrainian long-range drone strikes have repeatedly targeted Russian refineries and fuel depots in a campaign aimed at degrading the energy revenues that finance Moscow's war effort. Refineries sit at the center of that revenue stream, converting crude oil into the diesel and other products Russia exports.

The truce follows a more contentious announcement on Friday. After a phone call with Russian President Vladimir Putin, Trump said Russia would supply more than 300,000 tons of diesel immediately, 500,000 tons in November, 1 million tons after that, and a further 3 million tons soon afterwards. That totals about 4.8 million tons, or roughly 36 million barrels at a standard conversion rate.

The purchase deal marks a sharp turn from the sweeping Russia sanctions law Trump signed last month, which was aimed at choking off the oil and gas revenues that fund Russia's war. It also comes as high domestic fuel prices loom over next month's US midterm elections — with diesel a particularly sensitive channel, since it powers the trucking, farming and heating through which fuel costs reach consumers. Zelensky described the diesel arrangement as "a weak decision by strong partners" and said it would prolong the war.

Both announcements landed while US envoys Steve Witkoff and Jared Kushner were holding talks with Ukrainian officials in Miami on a proposal to end the conflict.

For oil, the two announcements point the same way for diesel: more Russian supply. The deal adds Russian barrels directly, while a halt to Ukrainian strikes on Russian fuel infrastructure would remove a recurring threat to the country's refining and export capacity — a combination that would weigh on diesel margins if it holds. Russia ranks among the world's largest diesel exporters, making its fuel flows a meaningful variable for global pricing. Traders are likely to discount both developments until details emerge, as the Kremlin has not publicly confirmed the truce terms and the delivery schedule rests on Trump's own description. The broader signal is a weaker US commitment to squeezing Russian energy revenues, which erodes part of the sanctions-related risk premium in crude.

Much now depends on details that have yet to surface: whether Moscow publicly commits to the truce, how it would be monitored, and whether the diesel shipments arrive on the schedule Trump set out. Without those, markets and Kyiv alike are working from a social media post.