Foreign Secretary William Hague has urged China to use its diplomatic leverage with North Korea by supporting fresh sanctions against the regime.
There is additional pressure which can be placed on North Korea, additional sanctions that can be put in place, but of course have the most effect if they have the strong support of China - a key nation in this regard.
China agreed that there would be significant action if this happened so we will now look to them to discuss this matter with them.
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.