The US is considering whether to take military action against Syria. This comes as a response to evidence that chemical weapons were used against civilians in that country.

Yesterday, Secretary of State John Kerry said that evidence of a chemical attack was "undeniable."

Today, Secretary of Defense Chuck Hagel said US forces were prepared to act should President Obama choose to pursue military action. For more on the likelihood of US intervention, we're joined by Jonathan Marcus, BBC diplomatic and defense correspondent.