On May 1, 1960, the USSR shot down an American U-2 spy plane that had entered its airspace. Believing the plane destroyed and the pilot dead, the U.S. declared it a weather plane. When Nikita Khrushchev announced the recovery of the plane and pilot, he gave Eisenhower a way out, suggesting the president was not aware of the flights. Eisenhower would not play along; he defended the flights but promised not to resume them. Three weeks later, at the start of the Paris summit to ease Cold War tensions, Khrushchev denounced the flights as "aggressive . . . treacherous, [and] . . . incompatible [with] . . . normal relations between states in times of peace." He continued, "We reserve the right to retaliate against those who . . . violate . . . national sovereignty." Later, Khrushchev acknowledged that "internal politics" forced him to react as he did.