US President Donald Trump has called for Ukraine to elect a new president, intensifying tensions with Ukrainian leader Volodymyr Zelenskyy over the ongoing war with Russia, rising American diesel prices and a controversial agreement to purchase Russian fuel.

Trump's remarks came after he announced a diesel supply agreement with Russian President Vladimir Putin, aimed at easing pressure on fuel prices in the United States. The move has triggered criticism from Kyiv and several European allies, who warn that renewed Russian energy revenues could strengthen Moscow's ability to continue its war against Ukraine.

The latest dispute threatens to deepen divisions between Washington and Kyiv at a time when diplomatic efforts to end the conflict remain uncertain.

Speaking to reporters at the White House on Saturday, Trump argued that Zelenskyy had failed to reach a peace agreement with Russia despite repeated opportunities.

“I think it's time for Ukraine to get a new president,” Trump said, suggesting that the country needed a leader willing to negotiate an agreement to end the war.

The US president also accused Zelenskyy of contributing to global diesel supply problems through Ukrainian attacks on Russian oil refineries. Trump has repeatedly urged Kyiv to stop targeting Russian energy infrastructure, arguing that the strikes have affected fuel availability and contributed to higher prices.

He also claimed that the war could have been avoided had he been president when Russia launched its full-scale invasion in February 2022.

Zelenskyy has rejected pressure to accept terms that could undermine Ukraine's security and territorial integrity. Ukraine's Foreign Minister Andrii Sybiha defended the president, saying that the Ukrainian people have the right to decide who leads their country.

Trump's intervention has added a new political dimension to the conflict, with questions emerging over Washington's approach to Ukraine and its future support for Kyiv.

The disagreement escalated after Trump announced an agreement with Putin for Russia to supply diesel to help address rising fuel prices.

According to Trump's announcement, Russia would initially supply more than 300,000 tonnes of diesel, followed by additional shipments in the coming months. The agreement is intended to increase available supplies and ease pressure on the American fuel market.

Diesel is particularly important to the US economy because it powers freight transport, agricultural machinery and other essential industries. Higher diesel prices can increase shipping and production costs, potentially adding to inflation and putting pressure on consumers.

Fuel prices have risen amid disruptions to global energy supplies linked to the wider conflict involving Iran and the closure of the strategically important Strait of Hormuz.

Trump has presented the Russian supply arrangement as a way to bring prices down, particularly ahead of the November US midterm elections.

However, the agreement has raised concerns because it appears to conflict with the administration's broader policy of using sanctions to limit Russian revenues during the war in Ukraine.

Russia has announced a partial lifting of restrictions on diesel exports, but it remains uncertain how quickly the additional supplies will reach international markets or how significantly they will affect prices.

Zelenskyy strongly criticised the agreement, arguing that additional Russian energy revenues could be used to finance weapons production, drone development and military operations.

The Ukrainian president linked the announcement to renewed Russian attacks on Ukrainian cities, warning that easing economic pressure on Moscow could encourage further aggression.

His criticism came after Russian strikes in the Zaporizhzhia region killed at least 20 people, including three children, according to Ukrainian officials. The attacks also injured civilians and caused damage to residential buildings.

Zelenskyy argued that Russia should face greater pressure to end the war rather than receive new opportunities to earn revenue from energy exports.

Kyiv has also expressed frustration over the timing of Trump's announcement, which came while US representatives were meeting Ukrainian officials in Miami to discuss proposals for ending the conflict.

A Ukrainian official told the Associated Press that Kyiv had not been informed of the diesel agreement before it was announced.

The agreement has also unsettled European governments that continue to support sanctions against Russia.

European officials have argued that energy exports remain an important source of revenue for Moscow and that restrictions are intended to limit the Kremlin's capacity to sustain its military campaign.

Sweden expressed regret over the agreement, while Germany reiterated its commitment to existing sanctions and continued support for Ukraine. Polish officials also questioned whether Russia could reliably supply the announced volumes given damage to its refining infrastructure and domestic fuel pressures.

The disagreement highlights a growing divide over how best to end the war: whether economic concessions could encourage negotiations or whether maintaining pressure on Russia remains essential to achieving a lasting settlement.

The immediate impact of the diesel agreement will depend on the volume of fuel delivered, its effect on international prices and the response from Washington's European partners.

The diplomatic consequences could be equally significant. If the United States reduces economic pressure on Russia while demanding that Ukraine limit attacks on Russian energy infrastructure, Kyiv may face increasing uncertainty over the future of American support.

For Zelenskyy, the challenge remains securing a peace settlement that protects Ukraine's sovereignty and long-term security. For Trump, the challenge is balancing domestic economic concerns with the wider geopolitical consequences of closer energy cooperation with Moscow.

With Russian attacks continuing and negotiations facing fresh complications, the latest dispute underscores how energy prices, sanctions and battlefield developments have become closely connected.

The key question now is whether Trump's Russian diesel deal can lower American fuel costs without further weakening Western efforts to pressure Moscow into ending the war in Ukraine.