WASHINGTON/LONDON/MOSCOW — US President Donald Trump said on Sunday that Russia and Ukraine had agreed to an immediate "energy ceasefire," but Ukrainian President Volodymyr Zelensky said he was unaware of any such agreement.

"Effective immediately," Trump wrote on his Truth Social platform, adding that "both parties have agreed."

However, Zelensky told US news outlet Axios that Trump's announcement "was news for me."

"But if Russians agree to an energy ceasefire, Ukraine will agree," Zelensky said.

ALSO READ: Putin, Trump discuss Ukraine crisis, energy supply over phone

On Saturday, Trump said Russia was willing to reach a deal to end the conflict in Ukraine, but accused Zelensky of resisting a negotiated settlement. He also called for Ukraine to hold an election and choose a new leader who could make a deal with Moscow.

"I think that Russia would like to make a deal," Trump told reporters, adding that "for whatever reason, Zelensky does not want to make a deal."

On Friday, Trump announced a deal with Russian President Vladimir Putin for Russia to supply diesel fuel to the United States and global markets.

The Kremlin said Friday that Ukrainian drone attacks during Russia's parliamentary elections had effectively derailed prospects for an immediate resumption of peace talks.

Zelensky criticized the move, saying that allowing Russia to sell petroleum products would amount to investing in the war. 

Defense secretary: Britain doesn't support Trump's Russia diesel deal

Britain does not support Trump's deal with Putin to purchase millions of tons of diesel from Russia, British Defense Secretary Wes Streeting said on Sunday.

"We don't support that decision. As the prime minister set out, we are strengthening sanctions against Russia," Streeting said in an interview broadcast by the BBC.

He added that the deal was done "very much in the context of the US midterm elections" in November and at a time when politicians across the world were under pressure to ease the cost of living.

Trump's diesel agreement is aimed at lowering fuel prices in the United States that have risen following the joint US-Israel attacks against Iran, according to the BBC report.

Russia strikes Ukraine data center, seizes 4 more settlements

Meanwhile, Russian forces carried out drone strikes overnight on Ukrainian military-related facilities and cargo vessels and captured four more settlements along the front line, the Russian Ministry of Defense said on Sunday.

Russian drones struck a data center in the southern Ukrainian city of Odessa that was used to process, transmit and store information for Ukrainian troops, the ministry said in a statement.

The drones also hit a cargo ship docked at the port of Chornomorsk in the Odessa region that had previously delivered supplies to Ukrainian forces, the ministry said.

On Sunday afternoon, Russian forces struck a logistics center in Ukraine's Mykolaiv region used to store military supplies, as well as a cargo ship that was transporting military supplies to the Port of Chornomorsk, it said.

The ministry also said Russia's Northern and Central army groups had each captured two settlements, in the Kharkiv and Donetsk regions, respectively.