The International Atomic Energy Agency says North Korea has made rapid progress

The International Atomic Energy Agency (IAEA) said Friday that North Korea's third nuclear test on September 3 showed that the country had made "rapid progress" in weapons research and development.

IAEA Director Amano said that the DPRK's sixth and most powerful nuclear test constitutes a "new threat".

"The most important thing now is the international community to unite," Amano's visit to Seoul and South Korean Foreign Minister Kang Jing and after the meeting, told reporters.