U.S. Secretary of State John Kerry said on Monday that Syria could prevent a military attack if President Bashar al-Assad handed over all his chemical weapons to the international community within the next week but expressed serious doubts that Assad would do so.

When asked by a reporter whether there was anything Assad's government could do or offer to stop an attack, Kerry said:

"Sure, he could turn over every single bit of his chemical weapons to the international community in the next week - turn it over, all of it without delay and allow the full and total accounting [of it] but he isn't about to do it and it can't be done."

Speaking to reporters in London, Kerry also stressed the relationship between Britain and the United States was as strong as ever despite the British parliament having decided not to join military action against Syria.