U.S. scientist J. Robert Oppenheimer, known as the "father of the atomic bomb," apologized to Japanese atomic bomb survivors who visited the United States after the end of World War II, officials at a Japanese nonprofit organization said Friday.

A video had been found in which a woman who interpreted the meeting between Oppenheimer and hibakusha said that the scientist was in tears when he gave the apology, according to World Friendship Center, based in Hiroshima, which was devastated by a U.S. atomic bombing in the closing days of the war.

There are no records of Oppenheimer, who led a U.S. project to develop atomic bombs, giving a formal apology over the bombing.

The video footage is about 50 minutes long and shows the late interpreter Yoko Teichler speaking in 2015 about a private meeting between two hibakusha from Hiroshima and Oppenheimer at Princeton University in 1964.

Oppenheimer apologized profusely while crying intensely as soon as he met the visitors, Teichler said in the footage.

Shizuo Tachibana, director of World Friendship Center, said that the footage had been taken as part of a video commemorating the 50th anniversary of the organization, but was not used and had been stored away.

"I hope this will be used as an opportunity for people to learn about the pleas of many hibakusha," Tachibana said.