The UK will provide "vital military assets" to help a Nato mission tackling people smugglers in the Aegean, David Cameron confirmed as European leaders gathered to discuss the migrant crisis in Brussels.
The Prime Minister, who will join counterparts from European Union nations and Turkey at a summit in Brussels, announced that the Royal Navy was deploying amphibious landing ship RFA Mounts Bay as part of the Nato deployment.
The ship, which carries a Wildcat helicopter, is expected to start operations in the coming days, spotting smugglers taking migrants to Greece and passing the information to Turkish coastguards so they can intercept the boats.
Two Border Force cutters will also join the operation, along with a third boat - the chartered civilian vessel VOS Grace - which is already in the Aegean.RFA Mounts Bay will join naval vessels from Germany, Canada, Turkey and Greece as part of Nato's first intervention in the migrant crisis.
This migration crisis is the greatest challenge facing Europe today.
At the summit, Mr Cameron is expected to call for work on breaking the link between people getting on a boat and being able to settle in Europe by "smashing" trafficking gangs and increasing the rate at which illegal migrants are sent back.
He will also urge support for Turkey, which already hosts 2.6 million migrants with many more sheltering on its border with war-torn Syria.Greece should also be given help to speed up the processing of migrant claims and assistance in returning illegal immigrants to their countries of origin.