Japan's Prime Minister Shinzo Abe has sternly rebuked his defence minister for saying the US atom bomb attacks during World War II were inevitable.
Shinzo Abe has an uphill struggle ahead of upper house elections
Fumio Kyuma has already apologised for his comments over the weekend, which angered bomb survivors and sparked opposition calls for his dismissal.
Mr Abe said he had told Mr Kyuma to "strictly refrain from making remarks that cause misunderstanding".
It comes as the prime minister faces his lowest ratings since taking office.
His 10 month premiership has been hit by a series of political scandals, including one involving missing pension records.
The latest surveys - putting his support at around 30% - do not bode well for Mr Abe as he prepares for upper house elections on 29 July.
'Couldn't be helped'
Mr Abe told reporters on Monday that he had delivered some stern words to his defence minister following Mr Kyuma's controversial remarks.
"Japan is the only country that suffered an atomic bomb. We need to always consider and stand in the position of the survivors," Mr Abe said.
Fumio Kyuma has faced a storm of protest over his comments
Following his meeting with the prime minister, Mr Kyuma said he had been told "to be careful about my comments."
"I'll follow his instructions," he said.
Mr Kyuma said in a speech to a university on Saturday that the bombs that landed on Nagasaki and Hiroshima in 1945 were "something that couldn't be helped".
The US, he said, must have thought the bombs "could prompt Japan's surrender, thus preventing the Soviet Union from declaring war against Japan".
Japanese leaders rarely comment on the use of atom bombs against Japan, for fear of damaging ties with the US.
Mr Kyuma, who is from Nagasaki and represents the city in parliament, later apologised for giving the impression that he lacked respect for the victims of the bombings.
He is not expected to resign.
But the gaffe has dealt another blow to Mr Abe's standing among the electorate.
A poll in the Asahi newspaper at the weekend found that his support had dropped to 28% - taking it to below 30% for the first time.
A survey in the Mainichi Shimbun newspaper on Monday put that figure at 32% - but reported that more than half of respondents said they did not support him, the highest percentage during his premiership.