WASHINGTON — When President Obama first visited Japan in November 2009, he said he hoped someday to visit Hiroshima and Nagasaki, where the United States dropped atomic bombs during World War II.

With his fourth and likely final visit to Japan as president scheduled this month for a Group of 7 meeting for leaders of industrialized nations, the White House is deciding whether Mr. Obama will follow through. No sitting American president has ever visited the cities, because of concerns that such a trip would suggest that the United States was apologizing for the attacks.

“The memories of Hiroshima and Nagasaki are etched in the minds of the world, and I would be honored to have the opportunity to visit those cities at some point during my presidency,” Mr. Obama said in 2009.

The calculus for a visit is particularly complicated for Mr. Obama. Political opponents have often falsely accused him of undertaking an “apology tour” of world capitals in his first year in office, so anything that even hints at atonement would feed that criticism.