Meanwhile, in Washington, Secretary of State Marco Rubio said the war is setting Ukraine back 100 years. Zelenskyy responded by inviting him to visit — to witness firsthand the destruction, but also see Ukraine's technological advancements, particularly in drone warfare, where he says Ukraine remains decades ahead of the world.

A shortage of infantry troops and supply routes under Russian drone attacks have dealt a blow to Ukrainian forces around the strategic eastern city of Pokrovsk.

Trump's Ukraine envoy said Sunday that both Kyiv and Moscow would have to make concessions if they are to successfully negotiate a solution to the ongoing war.