Japan's defence minister has apologised for saying the US atom bomb attacks in World War II were inevitable.
Mr Kyuma is an MP for Nagasaki
Fumio Kyuma's comments had outraged bomb survivors and sparked calls from opposition parties for his dismissal.
The minister said he was sorry if he had given the impression he lacked respect for the victims of the bombs dropped on Hiroshima and Nagasaki.
Speaking in Nagasaki, where he is from, Mr Kyuma promised not to make such remarks in the future.
He had said in a speech at a university that the bombing appeared to be "something that couldn't be helped".
The US, he added, must have thought the bombs "could prompt Japan's surrender, thus preventing the Soviet Union from declaring war against Japan".
Hiroshima has preserved some of its ruins from the blast
Japanese leaders rarely comment on the use of the atom bomb against Japan for fear of damaging ties with the US.
In a television debate, opposition politicians condemned Mr Kyuma's speech.
"As victims of atomic bombs, we never justify nuclear weapons no matter what the conditions are," said Takeaki Matsumoto, a senior MP in the Democratic Party.
Another MP, Tomoko Abe of the Social Democratic Party, said that Mr Kyuma was not fit to be defence minister and should resign.
The bombs which hit Nagasaki and Hiroshima, in a US bid to force Japan to surrender in 1945, killed about 240,000 people.
The row comes ahead of upper house elections on 29 July in which the ruling party faces dwindling public support.
THE ATTACK ON HIROSHIMA
0812 local time, 6 August 1945:
1. American B-29 bomber Enola Gay approaches Hiroshima at an altitude of about 9,357 metres, and begins its bombing run
2. At 0815 it releases the atomic bomb Little Boy
3. The aircraft then performs a sharp, 155-degree right turn and dives an estimated 518 metres
4. At 0816, the bomb explodes with a force of 13 kilotons at a height of approximately 576 metres above the city
5. About a minute later the first shock wave, travelling at about 335 metres per second, hits the aircraft