Trump calls for a change in Ukraine's president, Volodymyr Zelensky

(CNN) - On Saturday, US President Donald Trump called for a new president for Ukraine, criticizing current President Volodymyr Zelensky, in the context of the controversy over the diesel fuel deal that the United States concluded with Russia.

In response to a question from CNN journalist Kevin Liptak about concerns that the deal - which aims to supply markets with Russian diesel fuel - would prolong the war in Ukraine, Trump said: “Zelensky could have ended this war on many occasions... but he chooses not to do so.”

Trump strongly criticized Zelensky's move to target Russian refineries, claiming that the Ukrainian president "wants to cause trouble for the world."

Trump said: "You know what I'm suggesting? I'm suggesting that they bring in a new leader who can make a deal. He could make a lot of deals, but - for some reason - he never does."

Zelensky strongly criticized the agreement between the United States and Russia on diesel fuel, describing the new deal as “an investment in a war that must be ended, not prolonged.”

On Friday, Trump announced that he had reached an agreement with Russian President Vladimir Putin to supply the markets with Russian diesel fuel, as part of his efforts to reduce energy costs ahead of the midterm elections.

Trump said Putin had agreed to "immediately" supply more than 300,000 tons of diesel to global energy markets, with another 500,000 tons promised in November.

He explained that millions of additional tons of Russian diesel will be supplied following the first shipments "based on the condition of their diesel refineries."