President Trump on Sunday called out Ukrainian President Volodymyr Zelensky for targeting Russian diesel during the ongoing war with Russia, saying the strikes are causing a shortage. 

This comes after Trump held an hour-long phone conversation with Russian President Vladimir Putin, and US envoys Steve Witkoff and Jared Kushner traveled to Moscow and Kyiv last week to meet with the leaders of both countries.

Trump was asked by reporters if he'd spoken to Zelensky since his conversations with Russia's Putin, and called on Zelensky to stop hitting diesel refineries.

"Zelensky has to do one thing: He has to stop knocking out diesel fuel in Russia," Trump told reporters at the second day of the Irish Open on Sunday.

"Let him go after targets, but not diesel fuel, because he's causing a shortage of diesel. This isn't done by the Middle East. This is done by what's happening with Russia and Ukraine."

"So, we spoke to Mr. Zelensky about it. There are plenty of other targets. Don't hit diesel fuel because that's hurting— that's hurting the world. We don't want him to hit diesel fuel," Trump added.

"He's hitting diesel refineries."

Per the Associated Press:

Ukraine's recent long-range strikes have targeted Russia's oil and gas industry, which Kyiv says both funds and directly fuels its war on Ukraine. The Ukrainian drone campaign has caused fuel rationing across Russia , despite the country being a key oil and gas exporter. Other Ukrainian strikes targeted major Russian online retailers , bringing the war ever closer to the public.

Ukraine also claimed on Sunday to have hit a major oil refinery in Slavyansk-on-Kuban, in Russia's Krasnodar region, across from Crimea. The Defense Intelligence of Ukraine (DIU) agency said its drones struck a key oil processing unit and the refinery's tank farm overnight, sparking a massive blaze visible from dozens of kilometers (miles) away.

Krasnodar authorities said the strike on "an enterprise" in Slavyansk-on-Kuban injured three people, damaged an oil pipeline and started a blaze. They did not directly respond to the Ukrainian claims.