UN Security Council Resolution 2087 committed the Security Council to take significant action in the event of a further launch or nuclear test by North Korea.
The UK will begin urgent consultations with Security Council partners calling for a robust response to this latest development.
North Korea has a choice to make: it can either engage constructively with the international community, cease developing its nuclear and ballistic missile programmes and return to negotiations, or face increasing isolation and further action by the Security Council and the international community.
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.