In a visit to Hiroshima this month, President Barack Obama is the first serving U.S. president to travel to the city since the nuclear bombing in 1945.
The visit will be part of an Asian trip from 21-28 May that will also take in Vietnam.
The Hiroshima bombing on 6 August 1945 killed 140,000 people. Along with a second bombing on Nagasaki - it is credited with ending World War Two.
The White House said there would be no apology for the bombings.
A statement from Mr. Obama's press secretary read: "The President will make an historic visit to Hiroshima with Prime Minister [Shinzo] Abe to highlight his continued commitment to pursuing peace and security in a world without nuclear weapons."