KYIV/WASHINGTON, Oct. 11 - U.S. President Donald Trump unexpectedly declared on Sunday that Russia and Ukraine had entered an energy ceasefire that was “effective immediately,” though Ukrainian President Volodymyr Zelenskiy said he had yet to receive the agreement’s details.

Moscow made no immediate comment on Trump’s statement. The announcement came after several days of pressure from the U.S. president on Kyiv to stop striking Russian oil refineries. Trump has linked those attacks to higher diesel prices, an issue weighing on his Republican Party ahead of next month’s U.S. midterm elections.

Relations worsened sharply on Saturday when Trump told Zelenskiy he had “better damn well stop” targeting Russian refineries and suggested that Ukrainians choose a new leader in future elections. Trump said Zelenskiy had passed up multiple chances to reach an agreement with Moscow.

In a Sunday post on his Truth Social platform, Trump said without warning that both sides had accepted an energy ceasefire, though he gave no further information.

“Effective immediately, there is an ENERGY CEASEFIRE in the War between Russia and Ukraine. Both parties have agreed. Do not break it!” Trump wrote.

Trump had previously said in mid-September that an energy ceasefire had been arranged in Ukraine, but neither Moscow nor Kyiv publicly confirmed such an understanding at the time.

A person familiar with the matter said Washington had warned it could halt intelligence sharing with Ukraine and restrict weapons purchases through the Prioritised Ukraine Requirements List system while urging Kyiv to end attacks on Russian energy facilities.

The source said Zelenskiy was also in contact with European leaders in an effort to reduce tensions with Trump.

The White House did not immediately reply to a request for comment.

Zelenskiy said he had spoken about Trump’s ceasefire declaration with NATO Secretary General Mark Rutte, Canadian Prime Minister Mark Carney and Finnish President Alexander Stubb.

“Ukraine supports the ceasefire, and it is important that Russia support it as well. We are awaiting details from the American side,” Zelenskiy wrote on Telegram.

In his evening video address, Zelenskiy said Russian forces continued to attack Ukrainian energy targets, including a strike on a combined heat and power facility in Kharkiv, the country’s second-largest city. A Ukrainian official said the attack occurred after Trump announced the ceasefire.

Earlier in the day, Zelenskiy had rejected calls for Ukraine to stop attacking Russian refineries on its own. He repeated that Kyiv would consider doing so only if President Vladimir Putin ended Russian attacks on Ukraine’s power network.

Trump also urged Ukraine to hold elections, which have been suspended since Russia’s 2022 invasion. Zelenskiy said he would call a vote if Putin accepted a 60-day ceasefire.

Zelenskiy said Ukrainians alone should decide who leads the country, while stressing that fighting would first have to stop. Ukrainian law bars elections during martial law because of security concerns.

“Please tell Putin, give us two months, 60 days of total ceasefire, 60 days, and we will organise elections,” Zelenskiy said.

The Ukrainian president denied that Kyiv was responsible for rising energy costs, saying the wider conflict in the Middle East had played a much larger role in pushing up prices.

Global diesel prices rose sharply after the Iran war began in February, creating a political challenge for Trump’s Republican Party before the midterms, when Democrats could win control of one or both chambers of Congress.

On Saturday, Zelenskiy strongly criticised Trump’s announcement of a diesel supply arrangement with Russia, arguing that it would encourage Moscow to continue its attacks on Ukraine and lead to more deaths.

Under the arrangement outlined by Trump on Friday, Russia would promptly send more than 300,000 metric tons of diesel to U.S. and international markets, or roughly 2.25 million barrels of fuel. The United States exports about 1.5 million barrels of diesel a day.

Several U.S. lawmakers also objected to the diesel arrangement.

Republican Senator Thom Tillis of North Carolina said the planned diesel supply agreement with Russia could be unlawful and might endanger Americans.

In Kyiv, some residents reacted angrily to Trump’s suggestion that Ukraine should select another leader prepared to reach an agreement with Russian President Vladimir Putin.

“No one has the right to tell us what to do, especially since elections cannot be held during wartime,” said Sabina, a 40-year-old primary school teacher. “In my view, it is a betrayal by our partners,” she said of Trump’s comments.

Ukrainian officials said fresh Russian attacks on Sunday killed three people near a grocery store in Kharkiv and another three people in the western city of Ivano-Frankivsk.

Moldova, which borders Ukraine to the west, also reported another incursion involving what officials described as Russian drones. The aircraft reportedly landed around 35 km (22 miles) from the capital, Chisinau.