“I’m not happy with what Putin is doing. He’s killing a lot of people, and I don’t know what the hell happened to Putin. 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,” Trump told reporters in New Jersey on his way back to Washington, D.C Sunday night. “We’re in the middle of talking, and he’s shooting rockets into Kyiv and other cities.”

Trump said he is “very surprised” about what transpired, though just a week ago, Russia launched its largest drone attack against Ukraine — a day before Putin and Trump spoke on the phone.

“I don’t like what Putin is doing, not even a little bit. He’s killing people. And something happened to this guy, and I don’t like it,” Trump added Sunday.

Trump said Sunday he’s “absolutely” considering additional sanctions against Russia, which Ukrainian President Volodymyr Zelensky has called for.

Trump, who has often touted his good relationship with Putin, spoke with the Russian leader on Monday in an attempt to negotiate a 30-day ceasefire between Russia and Ukraine.

After the call with Putin, and subsequent calls with Zelensky and other European allies, Trump announced that “Russia and Ukraine will immediately start negotiations toward a Ceasefire and, more importantly, an END to the War.”

Trump added that conditions “will be negotiated between the two parties, as it can only be, because they know details of a negotiation that nobody else would be aware of.”

After Russia’s latest attacks, Zelensky said Sunday, “America’s silence, and the silence of others in the world, only encourages Putin.”

At least 12 people were killed in the attacks across Ukraine, including children, officials said. Dozens more people were injured.

Among those killed were three children from the same family in the Zhytomyr region — west of Kyiv — according to Ukraine’s internal affairs minister, Ihor Klymenko. He said their parents were hospitalized where the mother remains in a serious condition.

This story has been updated with additional details.