North Korea’s foreign ministry has criticized Japan over a remark by a senior government official, who said that Japan should possess nuclear weapons, describing it as a direct expression of the country’s long-time ambition.

The official is in charge of national security at the Japanese Prime Minister’s Office and made the comment on Thursday during a conversation with reporters that took place on the understanding it would be off the record.

The head of the North Korean foreign ministry’s institute for Japan studies issued a statement on Saturday, saying that the Japanese official’s remark was definitely not a gaffe. It says the remark rather directly revealed the ambition of being armed with nuclear weapons, which it claims is a status Japan has been dreaming of over the years.

The statement also criticizes Japan, saying it promotes a nuclear free world under a signboard that says it is the world’s only atomic-bombed country, while secretly trying to become a nuclear power.

The statement stresses that Japan’s “extremely dangerous and reckless military action” must be stopped.

Meanwhile, Pyongyang has been justifying its own nuclear and missile development, saying for example that it is countering the United States, and has maintained the stance of refusing to agree to denuclearization.

Some observers say North Korea could conduct nuclear testing in a very short period, if decided upon by leader Kim Jong Un.