The Ukrainian president's comments to Laura Kuenssberg came after he failed to sign the deal at the White House on Friday.
A judge has found that the mass layoffs of probationary government employees were likely unlawful. Newsweek's live blog is closed.
British Prime Minister Keir Starmer said on Thursday he had discussed with U.S. President Donald Trump a Ukraine peace deal that would be tough and fair, and that Britain was prepared to put boots on the ground and planes in the air to support it.
The war in Ukraine will be a focal point of the meeting between the US president and UK prime minister in Washington later.
British Prime Minister Keir Starmer rallied his European counterparts to shore up their borders and throw their full weight behind Ukraine.
Trump expressed confidence Russian President Vladimir Putin won't press to restart the war if a truce can be reached. "I think he'll keep his word."
After a meeting in the White House, Trump calls Starmer a "tough negotiator", adding: "He earned whatever the hell they pay him over there."
Heading to Washington for a meeting with U.S. President Donald Trump, Starmer again said Britain would "play our part" in any peacekeeping role in Ukraine, but could only do so with some kind of backup from the United States.