Russia launched a sweeping drone assault across Ukraine overnight into Sunday, targeting multiple regions, officials said, after U.S. President Donald Trump cast doubt over Russian President Vladimir Putin’s willingness to end the war.

Trump said Saturday that he doubts Russia’s Vladimir Putin wants to end his war in Ukraine, expressing new skepticism that a peace deal can be reached soon.

A version of this story appeared in CNN’s What Matters newsletter. To get it in your inbox, sign up for free here. Russia’s war on Ukraine may be entering a pivotal moment. President Donald Trump, who CNN reported Friday has been surprised and frustrated at the difficulty of achieving his promise of ending the war,