U.S. President Barack Obama said Sunday his visit to Hiroshima, the first city to suffer an atomic bombing, will emphasize friendly ties between former enemies, and reiterated he will not apologize for the devastating attack.

Obama will become the first sitting U.S. president to tour the site of the world's first nuclear bombing this Friday, accompanied by Prime Minister Shinzo Abe.

In an interview with NHK, Obama — who emphasized denuclearization early in his term — said the reality is that leaders often have to make hard choices during times of conflict and no apologies will be included in brief remarks he is expected to make during his visit to the city.