Barack Obama will announce during his first state visit to Britain this week that the White House is to open up its highly secretive national security council to Downing Street in a move that appears to show the US still values the transatlantic “special relationship”.

A joint National Security Strategy Board will be established to ensure that senior officials on both sides of the Atlantic confront long-term challenges rather than just hold emergency talks from the “situation room” in the White House and the Cobra room in the Cabinet Office…

Britain believes that co-operation between the British and US national security councils marks a significant step. One British government source said: “The US and UK already work closely together on many national security issues. The new board will allow us to look ahead and develop a shared view of emerging challenges, how we should deal with them, and how our current policy can adapt to longer-term developments.”