At 0400 GMT on 6 January North Korean state media claimed that it had successfully conducted its first hydrogen bomb test at 0130 GMT. The Comprehensive Test-Ban Treaty Organisation reported seismic signatures with a magnitude of 4.85, consistent with previous North Korean nuclear tests. We assess that the size of the seismic event caused by the nuclear test, while indicative of a nuclear explosion, is not indicative of the successful test of a thermonuclear weapon (also known as a hydrogen bomb); however this nuclear test is a serious violation of UN Security Council resolutions 1718, 1874, 2087 and 2094. North Korea’s nuclear and ballistic missile programme poses a significant threat to international security and regional stability. North Korea’s repeated provocations hinder the prospects for lasting peace on the Korean peninsula.
On 6 January I issued a statement strongly condemning the nuclear test as a grave breach of UN Security Council resolutions. While travelling in the region last week I spoke to my South Korean, Japanese and Chinese counterparts about the international response. I have also spoken to the US Secretary of State. The Minister of State for Foreign and Commonwealth Affairs, my right hon. Friend the Member for East Devon (Mr Swire), summoned the North Korean Ambassador to the Foreign and Commonwealth Office on 7 January in order to underline, in the strongest terms, the UK’s firm condemnation of this nuclear test and to make clear to North Korea that it can either engage constructively with the international community, or face increasing isolation and further action by the international community.
We worked to secure, and strongly support, the UN Security Council’s swift condemnation of this nuclear test in its statement following its emergency meeting on 6 January. The Security Council agreed that this North Korean nuclear test was a clear violation of existing Security Council resolutions; and that there should be a robust response including immediate work on further significant measures in a new Security Council resolution.
The UK remains deeply concerned by North Korea’s continued development of its nuclear and ballistic missile programmes. We continue to urge North Korea to return to credible and authentic multilateral talks on its nuclear programme, to abide by its obligations under the Nuclear Non-Proliferation Treaty, and to permit full access by the International Atomic Energy Agency.