U.S. President Donald Trump offered to help find a solution to the Ukraine war in a nearly 90-minute telephone call with Russian President Vladimir Putin, Kremlin aide Yury Ushakov said early Sunday.

Ushakov said Trump made the offer in the context of his participation next week at the NATO summit in Turkey.

He quoted the U.S. president as saying that U.S. envoys Steve Witkoff and Jared Kushner would continue their efforts at brokering a settlement and were prepared to make another visit to Moscow.

The Kremlin aide said Putin gave Trump a realistic assessment of the battlefield situation in Ukraine, where Russian commanders said on Friday that Moscow's troops had captured the strategically important city of Kostiantynivka.

On Saturday, President Volodymyr Zelensky and the General Staff rejected that claim, saying it still controlled the eastern city.