"No, he does not," Xinhua news agency quoted Earnest as saying on Monday when asked whether Obama thinks Japan deserves an apology for the bombing in 1945.
Earnest also said Obama is yet to decide whether to officially visit Hiroshima when in Japan in late May for a Group of Seven (G7) summit.
In April, US Secretary of State John Kerry visited the Hiroshima Peace Memorial Park, along with other G7 foreign ministers.
Kerry was the first US secretary of state to visit the A-bombed city, and Tokyo hopes Kerry's visit could spur a visit by Obama.
The US bombed Hiroshima city on August 6, 1945, and another nuclear bomb was dropped on the Japanese city of Nagasaki three days later, killing tens of thousands of people.
The bombings, which remain the only use of nuclear weapons for warfare in history, were thought to be instrumental in forcing the Japanese surrender in World War II.