A senior official at Japan’s Prime Minister’s Office has expressed the view that the country “should possess nuclear weapons.” But the official acknowledged that reviewing the nation’s Three Non-Nuclear Principles involves a huge political cost.

The official, who works on matters of national security, spoke to reporters on Thursday. The official made the case that Japan needs to strengthen its own deterrence amid the increasingly severe security environment.

The three principles call for not possessing, not producing and not permitting the introduction of nuclear weapons into the country. Japan is the only nation ever to have suffered atomic bombings during war.

The official added that there is no indication that Prime Minister Takaichi Sanae is thinking about reviewing the principles.

Takaichi confirmed during a Diet session last month that the government currently adheres to the principles as a set of policy guidelines.

Takaichi was also asked at the time whether language expressing Japan’s commitment to the principles would be retained when her government revises three national security documents. She replied that it was not an appropriate time for her to comment on the wording.