Donald Trump has called Ukraine’s renewed strikes on Russian oil refineries a “disgrace”, while renewing his criticism of Volodymyr ⁠Zelenskyy after an energy ceasefire between Russia and Ukraine collapsed.

Ukraine resumed strikes on Russian oil refineries ⁠after Zelenskyy said that Kyiv was abandoning a ceasefire abruptly declared by Trump last week, one that neither Russia nor Ukraine said they had agreed to.

In an interview with the Newsmax news outlet aired on Thursday, the US president said: “All he’s doing is making the world oil price higher. Well, I think that’s a disgrace.

“There are a lot ‌of targets you can ‌hit, but when you shoot at diesel refineries where you make, you know, ‌diesel oil, and we need that, and the world needs that, then he’s not doing a good service for the world.”

Relations between Kyiv and Washington have soured since last week, when Trump eased sanctions on Russia in exchange for Moscow releasing large amounts of diesel on to global markets.

Zelenskyy criticised the agreement, which was widely interpreted as an attempt to curb high fuel prices before the US midterm election, saying it would allow Russia to press on with its full-scale invasion of Ukraine that began more than four and a half years ago. US efforts under Trump to end the war have made no progress.

Trump repeated to Newsmax his views of the two leaders involved in the conflict. “I’m not a big fan of Zelenskyy,” Trump said. “I think they actually both would like to see it ⁠end, but I think I find Zelenskyy to be more difficult ​to deal with ​than Putin.”

Arriving in Brussels to meet EU leaders on Friday, Zelenskyy did not comment on Trump’s latest remarks. He said he was “so thankful that we have such huge support from the EU” and its leaders, whom he described as “real leaders”.

He went on to say that Ukraine wanted to end the war as quickly as possible, but “we don’t see now signals from [the] Russian side that they are ready for this”.

Kyiv’s relationship with Washington was strained further this week when Ukraine said Starlink services had been restricted, in effect hobbling Ukrainian drone strike missions and crucial air defences with a flick of the switch.

During a visit to London this week, the Ukrainian president said the sudden restriction of Starlink had left him feeling personally betrayed by Trump and lamented losing a partner.

The British defence secretary, Wes Streeting, said on Thursday that his US counterpart, Pete Hegseth, had assured him in a face-to-face meeting that the vital satellite communications system had been restored. In an interview with the BBC, he said it was unclear what had caused the disruption, but added: “This is not the first time we’ve seen a falling out between Washington and Kyiv.”

Amid growing doubts about long-term US commitment to Ukraine, European leaders declared their support for Zelenskyy.

Standing alongside the Ukrainian leader in Brussels, the European Council president, António Costa, said Ukraine could “count on us not only to support you in war” but also in the path to negotiating EU membership.

The European Commission president, Ursula von der Leyen, said the EU had supported Trump’s energy ceasefire, “but we have seen that Russia did not respect it, not a single minute” and instead had escalated its attacks. She said the EU intended to increase pressure on Russia, promising a 22nd round of sanctions, adding: “We will not lift any sanctions unless Russia stops the war.”

The promise of further European sanctions against Russia comes weeks after the EU lifted sanctions against two prominent Russian oligarchs at the request of France and Luxembourg.

After meeting Zelenskyy, the French president, Emmanuel Macron, said it was “crucial” that Ukraine received “all the means necessary to protect itself”.

The Polish prime minister, Donald Tusk, posted online: “I can reassure you, dear Ukrainian friends and President Zelenskyy: YOU ARE NOT ALONE.”

As Zelenskyy met Macron in Brussels, he said that the Kremlin had “launched yet another vile drone strike on Ukrainian energy infrastructure” in the city of Lutsk, which caused blackouts.

The Kremlin, meanwhile, accused Ukraine of derailing US peace efforts by resuming its strikes on refineries.