John Kerry: 'Russia's proposal must be swift and verifiable'

The US has said it will wait for details of a Russian proposal on Syrian chemical weapons but warned it would not permit "delays and avoidance".

US Secretary of State John Kerry said the plan must be "swift and verifiable" and warned its implementation would be "exceedingly difficult".

Syria has said it accepts the Russian plan to put the chemical weapons under international control.

The US, UK and France will table a UN Security Council resolution later.