The Ministry of National Defense, however, reaffirmed Seoul's longstanding policy of making the peninsula free of nuclear weapons.
"There's no change in our government's denuclearization principle," the ministry's spokesman Moon Sang-gyun said at a press report.
He was responding to a question about Defense Minister Song Young-moo's remarks a day earlier.
Speaking at a National Assembly session, Song said the possible return of the U.S. tactical nukes can be discussed as one of the various options for effective deterrence and response to the North's belligerence.
Amid the North's grave nuclear and missile threats, Moon added, the minister pointed out the need to "review all available options from the military perspective and find a realistic way."
In his meeting with U.S. Secretary of Defense Jim Mattis, Song talked about calls by some people, mainly conservatives, in South Korea for the deployment of the high-profile U.S. assets in Korea.
The U.S. withdrew the weapons from the peninsula in the early 1990s after the two Koreas agreed to denuclearize it.
South Korea's presidential office Cheong Wa Dae announced last week that for now, it's not considering the redeployment of the U.S. nuclear weapons, source from the Yonhap.
