London: To prevent terrorism activities, Britain will unveil a new joint secretary at the commencement of the US President Barack Obama’s two-day visit to London.

The "National Security Strategy Board" will be chaired by British National Security Adviser Peter Ricketts and his US counterpart, Tom Donilon, and is being established to help coordinate long-term foreign policy agendas.

Details of the initiative are due to be announced on Tuesday, as Obama arrives in Britain to begin a two-day official state visit.

"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," an adviser to British leader David Cameron said.

"It reflects a welcome further development of our close relationship on foreign and defence business," he added.

The board, which is expected to meet several times a year, will address the response to the ongoing "Arab Spring" uprisings as part of a broader brief to examine rogue states and the threat from international terrorism.

British Foreign Secretary William Hague maintained on Sunday that the "special relationship" between the two countries remained strong despite suggestions in Britain that Obama was not as UK-friendly as some of his predecessors.

"It is very special. I think the longer a US administration is in power the more they appreciate that," he said.

"You can see that in government," he added. "The co-operation that I see every day in intelligence matters is without parallel in the world.

"So is our nuclear co-operation. Our armed forces are working together with intimate closeness."