With 41 military aircraft impacted, the Ukrainian drone attack was described by some commentators as Russia's "Pearl Harbor." The attack on Pearl Harbor in December 1941 was a surprise air raid by Japan on the U.S. during World War II. Kyiv's assault follows ground advances by Moscow troops in recent days in Ukraine's Sumy border region.

Ukrainian President Volodymyr Zelenskyy on Sunday praised Ukraine's Security Service for "brilliant operation" aimed at "military targets" on Russian territory.

Russian President Vladimir Putin signed a decree that forces Ukrainians to legalize their status in occupied territories — or leave. Already, many Ukrainians had been forced to accept Russian citizenship in occupied areas to maintain their homes or access to health care and education.

Russian drone and missile attacks on Ukraine on Saturday killed at least two people, including a 9-year-old girl, officials said, as uncertainty remains about whether Kyiv diplomats will attend a new round of peace talks proposed by Moscow for early next week in Istanbul.