TOKYO — As Japan marks the anniversary of the 1945 atomic bombs, its leaders are pushing for a renewed debate on nuclear weapons in a challenge to the nation’s long-time pacifist stance.

Japan’s constitution renounces offensive military force, and successive governments have maintained a decades-old pledge not to possess nuclear weapons, produce them or permit their introduction into the country.

That commitment is now under pressure as East Asian neighbours – notably China – boost their military capabilities, while doubts persist about the reliability of Tokyo’s biggest security backer, the United States.

Prime Minister Sanae Takaichi has refused to clarify whether she will maintain the stance known as the three non-nuclear principles, and Defence Minister Shinjiro Koizumi called last month for a “discussion without a taboo” on the subject.

In December, an unnamed senior administration official told local media in an off-the-record session suggesting that Japan should possess nuclear weapons.

The remark was widely reported by major Japanese outlets including national broadcaster NHK and Asahi Shimbun, sparking public criticism.

“If I look at it cynically, I can’t help but think that maybe she really wants to change” Japan’s anti-nuclear commitment, 82-year-old Satoshi Tanaka, a campaigner who survived the 1945 attack on Hiroshima, told AFP.

The country marked the 81st anniversary of the Hiroshima bombing on Thursday and will do the same on Sunday to commemorate the attack on Nagasaki.

The August 1945 assault by the United States killed more than 210,000 people, including many from the effects of radiation exposure.

It remains the only time that atomic weapons have been used in warfare, and was one of the last major acts of World War II.