Why did general Dwight Eisenhower oppose using nuclear weapons in japan?

He believed that Japan was already defeated and would not pose a problem and that they were just prolonging to war to avoid looking like a humiliated army. He believed also that this would show the US in a new light as a country that dropped nukes on a defeated country and even more so because of civilian targets. He supported usage of nukes on military targets but did not want them to be used on civilian targets.