Ukrainian President Volodymyr Zelenskyy on Monday said Russia carried out strikes, despite US President Donald Trump claiming a "ceasefire" had been agreed over the weekend.

Trump announced unilaterally on social media on Sunday evening that "both parties" had agreed to an "energy ceasefire" which was "effective immediately."

There was no immediate ​confirmation ⁠from Moscow and Zelenskyy told the news site Axios within minutes of Trump's claim that the ceasefire was "news for me."

Ukrainian energy facility attacked

On Monday morning, Zelenskyy told the annual Warsaw Security Forum that there had been "Russian ​violations of the energy ​ceasefire announced President Trump" overnight, while the mayor of the northeastern city of Kharkiv reporting at least 12 injuries in attacks on energy facilities.

"It was clear that [Russian President Vladimir] Putin does not read Truth Social," Zelenskyy said, referring to Trump's social media platform.

"If Russia wants us to stop our long-range strikes against its oil refineries and oil exports, then it must stop its strikes against our energy system and critical infrastructure and stop killing our people," he said via video link, adding that he learned about the apparent ceasefire through the media.

Russia attacking civilians and infrastructure 

Beyond targeting Ukraine's energy infrastructure, Russian strikes hit a high-rise apartment building in the capital Kyiv on Monday, killing one person and injuring a further 11 according to Mayor Vitali Klitschko.

Attacks on Kyiv and other cities have largely been conducted at night, though the frequency of these has increased and now disrupt life in Ukraine around the clock.

In eastern Ukraine, three civilians were killed in a Russian rocket attack in Donetsk on Monday. And Ukrainian officials say another four civilians were injured in an attack in Kramatorsk.

Zelenskyy: Ukraine 'will respond' if no ceasefire

Zelenskyy expressed readiness in principle to back an agreement to refrain from attacks on energy infrastructure, but said such a ceasefire must be backed up by security guarantees.

"This ceasefire, it can work, and it can ​become ⁠a major step toward ending the war if ⁠the ​Americans truly step in now and make sure Russians respect it," he said.

"We are waiting for the ​of the conditions between the Americans and Russians, and we are waiting to ​see one specific step the Americans are ready to take.

"If Russia does not agree to an energy ceasefire, we will respond."

EU: No sign of Russia sticking to ceasefire

The European Union's foreign affairs chief Kaja Kallas said on Monday at a meeting of EU foreign ministers in Luxembourg that the bloc would "welcome the energy ceasefire if it holds" but added: "We haven't yet seen that Russia will also stick to it."

French President Emmanuel Macron also insisted that a "real ceasefire" be "respected by both sides" but said: "I ​have ⁠not noted, over the last 48 ⁠hours, ​any energy ceasefire coming from the Russian side."

The Russian government said on Monday that President Putin would only consider a ceasefire for a single day in the event that Ukraine intended to hold a presidential election.

The Kremlin earlier rejected ​a 60-day election ceasefire idea proposed by ⁠President ​Zelenskyy.

"I do not think he deserves a respite," said Russian Foreign Minister Sergei Lavrov.

Edited by: Jenipher Camino Gonzalez