U.S. Secretary of State John Kerry walks onto the podium for his joint news conference with Britain's Foreign Secretary William Hague (L), at the Foreign and Commonwealth Office in London September 9, 2013. Kerry said on Monday Syrian President Bashar al-Assad could avoid a military strike by turning over all his chemical weapons within a week but immediately made clear he was sure that would never happen. REUTERS/Alastair Grant/pool (BRITAIN - Tags: POLITICS CONFLICT)