Japan said on Tuesday it has the legal right to develop nuclear weapons despite its pacifist constitution but has no intention even to consider the long-taboo idea.
Prominent lawmakers have called on Japan, the only nation to suffer nuclear attack, to debate the nuclear option after communist neighbour North Korea on October 9 said it had tested its first atom bomb.
Chief Cabinet Secretary Yasuhisa Shiozaki argued that the US-imposed pacifist constitution allows Japan "the right to possess minimum capability" for self-defence.
"Theoretically and technically, nuclear weapons might be included in this, but this is different from the government's policy," said Shiozaki, the top government spokesman.
"The government has no intention of changing its three-point non-nuclear principles, nor the intention of discussing the issue," he told a news conference.
He was responding to the latest remarks by Shoichi Nakagawa, the policy chief of the ruling Liberal Democratic Party, who wants Japan to discuss going nuclear in light of the North Korean threat.
"The government sticks to its policy of not having nuclear weapons, but the government also says that it is allowed to have nuclear weapons under the constitution," Nakagawa said Monday.
Nakagawa is a close aide to Prime Minister Shinzo Abe, who strongly supports revising the constitution to give Japan a more active military role.
But Abe has repeatedly ruled out discussing the nuclear option.
The Japanese cities of Hiroshima and Nagasaki were obliterated by US nuclear bombs at the end of World War II that killed more than 210,000 people.
The United States has ensured Japan's security since then and forced it to renounce its right to a military.