President Volodymyr Zelensky has said he is "only standing up for Ukraine's interests" after scathing criticism from Donald Trump, who said he was "more difficult to deal with than [Russian President Vladimir] Putin".
The US president, who recently made a controversial deal with Moscow to import diesel, said Kyiv's new wave of strikes on Russian oil refineries was a "disgrace".
Zelensky said he could not accept the diesel deal because it might be followed by a gas agreement. "If I don't stand up to this... who else will do this?" he said at an EU summit in Brussels.
Tensions between Washington and Kyiv escalated over the diesel deal and curbs on Ukraine's battlefield satellite network.
However Zelensky said that he hoped US and Ukrainian negotiators would agree to a meeting "at one level or another" soon.
A news conference after the EU summit ended on a telling 15 seconds of silence, when Zelensky was asked by Sky news if he felt Trump was using him as a scapegoat for his own political problems.
After a long silence, Zelensky broke out into a grin, prompting laughter from the journalists in the room. "This is my answer," he said.
He arrived at the summit flanked by European Commission President Ursula von der Leyen and European Council President António Costa, and thanked the "real leaders" in Europe who were supporting Ukraine.
Trump has heavily criticised Zelensky for resuming strikes on Russian oil refineries, after the US president suddenly announced a Russia-Ukraine ceasefire on energy infrastructure last week.
Kyiv said it would stop strikes if Russia did the same but Moscow said it had never agreed to the deal and continued its attacks. After three days, Zelensky said Kyiv would resume its strikes.
"Of course we supported President Trump's energy ceasefire but we've seen that Russia did not respect it, not a single minute," Von der Leyen told reporters before the summit, adding that sanctions on Russia "[had] to increase".
The summit's agenda focused on funding for Ukraine and helping it get through another cold winter - the fifth since Russia launched its full-scale invasion in February 2022.
"Russia is trying everything to destroy the energy and water infrastructure," Von der Leyen told Zelensky, "but we stand by your side, we support you as we did in the other winters."
Zelensky said his country wanted the war to end "as quick as possible" but added that Russia was not showing signs that it wanted the same thing.
"That's why we have to prepare for the winter. A winter package is not only energy, it's also defence and funding," he said.
Deadly attacks on Ukraine continued overnight, with several people killed in a Russian drone strike in the north-eastern city of Kharkiv, while some 270,000 households were without power after strikes in the western Volyn region, the local governors said.
Trump's comments about Zelensky, during an interview with US outlet Newsmax on Thursday evening, reflect the deteriorating relationship between the US and Ukraine.
The US president said he was "not a big fan of Zelensky" and that he was "not a good guy for us to deal with".
"He doesn't want to settle," Trump said. "He says he wants to settle, but he doesn't."
"As you know, Putin hates Zelensky, and Zelensky hates Putin," he added. "And when you have that kind of hatred, it's very hard to get something settled."
The Kremlin later said it agreed with Trump's assertion that Zelensky did not want to make a deal with Russia. It is the same accusation that Kyiv has levelled at Moscow.
When asked about Ukraine's renewed strikes on Russian oil refineries, Trump said it was "a disgrace".
"All he's doing is making the world oil price higher... There are a lot of targets that you can hit."
Trump is frustrated at Ukraine's continued targeting of Russian oil refineries because it affects Moscow's ability to export its diesel to America, as per the deal the US recently made with Russia, in an effort to bring down fuel prices.
Since the war with Iran started in February, US fuel and especially diesel prices have skyrocketed, souring Trump standing with the American public - something he wants to fix before next month's mid-term elections.
The diesel deal infuriated Zelensky, who called it a gift to Putin and an "investment in a war that must be ended, not prolonged".
His anger was further heightened earlier this week, when restrictions were placed on the US-owned Starlink internet network, which is critical for Kyiv's military abilities to defend itself.
On Tuesday night, when the communications network was restricted, there were several deadly Russian strikes on Ukraine, with residents and the government saying there was no prior warning of the incoming attack.
On Friday, Zelensky called the slowdown a "very dangerous and unpleasant surprise". saying that Starlink speeds were still not fully restored.
The Trump administration had previously warned that it could withhold intelligence-sharing - crucial for Ukraine's defences - if Kyiv does not stop hitting Russia's oil refineries.
