US and UK to fight Islamist extremism and terror together

Britain and the US are to share expertise on preventing radicalism and tackling domestic "violent extremism".

Prime Minister David Cameron announced the move following talks with President Barack Obama at the White House, warning that they both faced a "poisonous and fanatical ideology".

Earlier, the two leaders agreed to conduct joint cyber-security war games and establish a "cyber cell" to enable security agencies from both countries to pool intelligence.

Nick Robinson reports.