Mr. Billingslea said these conditions, in addition to the obligations of the New Treaty, include addressing China's rapid and worrying strengthening of its nuclear capacity and concerns about Russia-related allegations. The US also wants to ensure an effective verification regime to restore trust that all three parties will comply with the commitments of the New START.

Mr. Billingslea and Russian Deputy Foreign Minister Serge Ryabkov on Monday conducted negotiations on the extension of the New START, a bilateral treaty that restricts both countries’ nuclear arsenals which will expire next February. Russia wants the current agreement to be extended for another five years, while the US demands a multilateral treaty that includes China, who declined an invitation to join.