US president Donald Trump fired off a screed against Vladimir Putin on Truth Social on Sunday night, saying the Russian president has “gone absolutely CRAZY.”

His statement on the social media platform followed brief remarks to reporters before boarding Air Force One, saying he’s “not happy” with Putin and that “he’s killing a lot of people.”

“And I don't know what the hell happened to Putin,” he told reporters. “I've known him a long time, always gotten along with him, but he's sending rockets into cities and killing people.”

On Truth Social, he wrote: “He is needlessly killing a lot of people, and I’m not just talking about soldiers. Missiles and drones are being shot into Cities in Ukraine, for no reason whatsoever. I’ve always said that he wants ALL of Ukraine, not just a piece of it, and maybe that’s proving to be right, but if he does, it will lead to the downfall of Russia!”

Mr Trump also said that Volodymyr Zelensky is “doing his Country no favors by talking the way he does.”

“Everything out of his mouth causes problems, I don’t like it, and it better stop,” Mr Trump wrote. “This is a War that would never have started if I were President. This is Zelenskyy’s, Putin’s, and Biden’s War, not ‘Trump’s,’ I am only helping to put out the big and ugly fires, that have been started through Gross Incompetence and Hatred.”

Russian forces mounted the largest aerial attack on Ukraine since the start of the war in 2022, killing at least 12 people, including three children.

Russian forces launched a barrage of 367 drones and missiles at Ukrainian cities overnight, including the capital Kyiv, the highest number of strikes in a single night since the invasion.

The dead included three children in the northern region of Zhytomyr, local officials there said.

Ukrainian president Volodymyr Zelenskiy called on the United States, which has taken a softer public line on Russia and its leader, Vladimir Putin, since President Donald Trump took office, to speak out.

"The silence of America, the silence of others in the world only encourages Putin," he wrote on Telegram.

"Every such terrorist Russian strike is reason enough for new sanctions against Russia."

Russia and Ukraine swapped hundreds more prisoners of war in the third and final part of the biggest exchange between the countries.

Russia's Defence Ministry said each side exchanged 303 soldiers, following the release of 307 combatants and civilians each on Saturday, and 390 on Friday, the biggest total swap of the war.

Ukraine's president Volodymyr Zelensky confirmed Sunday's exchange, saying on X that "303 Ukrainian defenders are home."

Hours earlier, the Ukrainian capital, Kyiv, and other regions came under a massive Russian drone-and-missile attack that killed at least 12 people and injured dozens.

Ukrainian officials described it as the largest aerial assault since Russia's full-scale invasion of Ukraine in February 2022.