No, the US didn't try and claim the U2 was a weather balloon, though they did try and claim that it was a routine weather survey: >...At first, and before they

No, the US didn't try and claim the U2 was a weather balloon, though they did try and claim that it was a routine weather survey: >...At first, and before they had confirmation that Powers had survived, U.S. officials claimed that the U-2 had been conducting a routine weather flight but experienced a malfunction of its oxygen delivery system that had caused the pilot to black out and drift over Soviet air space. On May 7, however, Khrushchev revealed that Powers was alive and uninjured, and clearly had not blacked out from oxygen deprivation. Moreover, the Soviets recovered the plane mostly intact, including the aerial camera system. It became instantly apparent that the weather survey story was a cover-up for a spy program. https://history.state.gov/milestones/1953-1960/u2-incident https://history.state.gov/milestones/1953-1960/u2-incident