Palm Beach, Florida - Donald Trump said Sunday he had "productive" talks with Russian leader Vladimir Putin hours before the US president meets Ukraine's Volodymyr Zelensky, in a year-end sprint to seal a deal to end the war.

Trump's renewed upbeat tone comes despite wide skepticism in Europe about Putin's intentions after Russia carried out another massive bombardment of the Ukrainian capital Kyiv just as Zelensky was heading to Trump's Florida estate.

"I just had a very good and productive telephone call with President Putin of Russia," Trump announced on his Truth Social platform.

Trump is set to meet Zelensky at 1:00 PM ET in the dining room of his Mar-a-Lago estate, where he frequently brings both foreign guests and domestic supporters.

Trump has made ending the Ukraine war a centerpiece of his second term as a self-proclaimed "president of peace," and he has repeatedly blamed both Kyiv and Moscow for the failure to secure a ceasefire.

Zelensky, who has faced verbal attacks from Trump, has sought to show willingness to work with the contours of the US leader's plans, but Putin has offered no sign that he will accept it.

Sunday's meeting will be Trump's first in-person encounter with Zelensky since October, when the US president refused to grant his request for long-range Tomahawk missiles.

And the Ukrainian leader could face another hard sell this time around, with Trump insisting that he "doesn't have anything until I approve it."

The talks are expected to last an hour, after which the two presidents are scheduled to hold a joint call with the leaders of key European allies.