Eisenhower could have made the information public. A lie of omission is still a lie.
https://en.wikipedia.org/wiki/Missile_gap
> According to Robert McNamara, Kennedy was leaked the inflated US Air Force estimates by Senator Stuart Symington, the former Secretary of the Air Force. Unaware that the report was misleading, Kennedy used the numbers in the document and based some of his 1960 election campaign platform on the Republicans being "weak on defense."[5] The missile gap was a common theme.
> Eisenhower refused to refute the claims publicly for fear that public disclosure would jeopardize the secret U-2 flights. Consequently, Eisenhower was frustrated by what he conclusively knew to be Kennedy's erroneous claims that the United States was behind the USSR in its number of missiles.[6]
> In an attempt to defuse the situation, Eisenhower arranged for Kennedy and Lyndon Johnson to be apprised of the information, first with a meeting by the Joint Chiefs of Staff, then Strategic Air Command, and finally with the Director of the CIA, Allen Dulles, in July 1960. Still, Kennedy continued to use the same rhetoric, which modern historians have debated as likely being so useful to the campaign that he was willing to ignore the truth.
If you want an explicit lie, the Eisenhower administration lied to the US public saying that the U-2 was for high-altitude weather research. When Powers was shot down, the official US lie was that a high-altitude research flight was missing, and may have 'drifted with an incapacitated pilot across the Soviet border' - https://en.wikipedia.org/wiki/Lockheed_U-2 .