Trump wrote on his Truth Social network that Ukraine had agreed not to strike Russian energy infrastructure facilities, and that Russia had taken on the same obligation.
He also said the rise in global diesel prices is caused mainly by the war between Russia and Ukraine, not by US military action against Iran.
Neither the Russian nor the Ukrainian side has so far commented on Trump's statement.
A day earlier, the US president publicly urged Volodymyr Zelensky to stop strikes on Russian enterprises that produce diesel fuel. Commenting on that appeal, the Kremlin said it welcomed the initiative, Meduza reports. According to the outlet, however, Moscow did not promise to stop strikes on Ukrainian economic infrastructure facilities if Kyiv halts strikes on Russian oil refineries.