What Cold War incident broke off important talks between Eisenhower and Khrushchev in 1960?

The Cold War incident that broke off important talks between President Dwight D. Eisenhower and Premier Nikita Khrushchev in 1960 was the U-2 incident. On May 1, 1960, an American U-2 spy plane was shot down over Soviet airspace, and the U.S. initially denied the mission's purpose. When the Soviet Union produced the pilot, Francis Gary Powers, and evidence of espionage, it led to a significant diplomatic crisis. Consequently, the planned summit in Paris between the two leaders was derailed, heightening tensions between the superpowers.