Leaders discuss Syria crisis at G20 summit
5 September 2013 Last updated at 22:45 BST
World leaders are locked in a divisive debate over Syria, at the end of the first day of the G20 summit in Russia.
US President Barack Obama is seeking support for military action, but Russia and China have issued a warning to the US not to take action without UN backing.
Meanwhile, David Cameron said the UK has fresh evidence of the use of chemical weapons in Damascus.
Nick Robinson reports.