Question to the Foreign, Commonwealth & Development Office:

To ask the Secretary of State for Foreign and Commonwealth Affairs, what discussions he has had with his US counterparts on the ratification by that country of the Comprehensive Nuclear Test Ban Treaty.

The UK is a strong supporter of the Comprehensive Nuclear Test Ban Treaty (CTBT). During the past 12 months, officials have discussed US ratification of the CTBT with US counterparts in a range of bilateral meetings and during the London Conference of P5 Nuclear Weapon States in February 2015. In addition, the UK has called for ratification of the Treaty by all remaining Annex II countries (which includes the US) at the Non-Proliferation of Nuclear Weapons Review Conference, the London P5 Conference, the G7 Non-Proliferation Directors Group, the 69th UN General Assembly First Committee and at the Seventh CTBT Ministerial Meeting.