LOS ANGELES - US President Donald Trump on Sunday made harsh remarks on both Russian President Vladimir Putin and Ukrainian President Volodymyr Zelensky.

"I'm not happy with what Putin's doing," Trump told reporters before he took Air Force One from Morristown, New Jersey back to Washington, DC.

"I don't know what the hell happened to Putin," he said.

"I've known him a long time. Always gotten along with him. But he's sending rockets into cities and killing people and I don't like it at all. OK. We're in the middle of talking, and he's shooting rockets into Kiev and other cities. I don't like it at all," he added.

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Trump made these remarks after Russia and Ukraine conducted large-scale drone and missile attacks on each other on Sunday.

Russia intercepted and destroyed 110 Ukrainian drones across various regions of the country overnight, including 13 over the Moscow region, the Russia Defense Ministry said Sunday.

Meanwhile, the Kiev authority said at least 12 people, including three children, were killed and dozens of others injured across Ukraine in a combined missile-drone attack launched by Russia early Sunday.

Later on Sunday evening, Trump wrote in a Truth Social post that Putin "has gone absolutely CRAZY!"

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He then turned to Zelensky, saying he was doing his country "no favors by talking the way he does," a reference to statements Zelensky made earlier on Sunday criticizing US silence on the latest Russian attacks.

"Everything out of his mouth causes problems, I don't like it, and it better stop," Trump said of Zelensky. Trump noted that he should not be blamed by Ukraine since "This is Zelensky's, Putin's, and Biden's War, not Trump's."