North Korean leader Kim Jong-un has recently been photographed with an unknown woman, causing international buzz.
Once completed, the North Korean reactor would be able to produce enough plutonium for a new bomb every year, according to the US-Korea Institute at Johns Hopkins University.
The threat of such a test, coming amid plans to test a controversial rocket this week, is seen as an effort by North Korea to extort more aid from the international community.
Kim Jong-il is widely reported to be hosting a rare political conference in North Korea – but what is really happening remains a secret.
A third nuclear test and naval confrontations in the Yellow Sea are likely, say analysts, in response to South Korean President Lee Myung-bak's announcement Monday of retaliatory measures against North Korea for torpedoing the navy ship Cheonan.