North Korea has denied that it is developing nuclear arms.

We have to develop more powerful and new arms to protect ourselves.

It usually takes a serious security threat to prompt countries to develop nuclear arms.

States like Pakistan have developed nuclear arms without testing them.

No state has yet developed nuclear arms just to imitate others or to boost its prestige.

That young man was developing short arms and low pockets.

In response, the federal government switched from developing nuclear arms to maintaining them.

"We don't think it was a government policy to develop nuclear arms," he told reporters on Friday.

South Korea was stopped by Washington from developing nuclear arms several decades ago.

And without tests, no nation seeking to develop nuclear arms could know for sure whether its weapons worked.