After becoming the first U.S. representative to attend Hiroshima's annual ceremony in 2010 to mark the 1945 U.S. atomic bombing, former U.S. Ambassador to Japan John Roos revealed Friday that he had recommended to President Barack Obama that the U.S. leader also visit the city.

"I think that it's important for every American to go there, and I think every president," Roos said.

Roos said he told Obama that attending the Peace Memorial Ceremony on the 65th anniversary of the Aug. 6, 1945, atomic bombing had been an "emotional" and "powerful" experience.