|US Secretary of State John Kerry|
US Secretary of State John Kerry has called for a reneweddiplomatic effort to end the conflict in Syria.
Speaking after talks in London, he said what he described as Russia's new focus on fighting Islamic State militants could be an opportunity to push towards a political settlement.
He said this was all the more urgent as violence in Syria was the "root cause" of Europe's current migrant crisis.
The EU, which is divided on the issue, is to hold emergency talks next week.
Mr Kerry is on a European tour which is expected to be dominated by the Syrian conflict.
After talks with his UK counterpart Philip Hammond on Saturday, he said they "agreed completely on the urgency of nations coming together in order to resolve this war that has gone on for much too long".