North Korea's fifth and most powerful nuclear test has been called provocative, unacceptable and intolerable.
Three days after Friday's launch, South Korea is warning that its neighbour is capable of another test any time.
The United Nations has promised new measures against Pyongyang with some countries, including the United States, calling for tougher sanctions.
But even that does not seem to faze the North Korean government, which says the threat of more sanctions is "laughable".
What can be done about North Korea's controversial nuclear programme?
Presenter: Adrian Finighan
Guests:
Victor Gao - director of the China National Association of International Studies
Daniel Pinkston - lecturer of international relations at Troy University
Jim Walsh - research associate at MIT's Security Studies Programme
