David Cameron and Barack Obama in anti-terrorism vow

David Cameron and Barack Obama have vowed to defeat the "distorted ideology" of terrorism, ahead of talks in Washington.

The UK and US leaders said they would not allow anyone to "muzzle free speech" after Islamist gunmen killed 17 people in terror attacks in Paris.

They are expected to discuss cyber crime and the economy during the prime minister's two-day visit.

It is likely to be his final Washington visit before May's general election.

Nick Robinson reports.