Why was the summit meeting between the leaders of the US and the USSR canceled?

The summit meeting between the leaders of the US and the USSR was canceled primarily due to rising tensions following the U-2 incident in May 1960, where an American spy plane was shot down over Soviet airspace. This incident severely strained diplomatic relations, leading to the cancellation of the planned meeting between President Eisenhower and Premier Khrushchev. Additionally, the Cold War climate and differing political agendas contributed to the inability to reach a consensus on key issues.