A nuclear test has been carried out in North Korea, Foreign Secretary William Hague described it as a "violation of United Nations Security Council resolutions".
Speaking on Daybreak, security expert Dr Sally Leivesley said it is likely the blast was "a little bit" smaller than the one which flattened Nagasaki, in World War II.
She added that this could mean the test used the same sized capacity of weapons, and the possible use of rockets for delivery.
Welcome to a more dangerous world, welcome to a world with a new nuclear power and to a world where the global powers are threatened.
Testing nuclear weapons is North Korea's way of saying we can defend ourselves, you have to take us seriously.