Defence Secretary Sir Michael Fallon said 500 troops will work alongside the 120 stationed on the islands to tackle law and order.
Speaking on BBC One’s The Andrew Marr Show, he said: “There has been a security issue there and that’s why we’re now prioritising getting armed troops in and police to strengthen the local police force.”
Sir Michael hit back at criticism over the Government’s response to the disaster.
He said they had prepared for hurricane season by sending to the region a 16,000 tonne aid ship, RFA Mounts Bay, equipped with supplies, marines and a helicopter.
He said: “We pre-positioned our ship there to help on the islands.” He also confirmed a second ship, HMS Ocean, had been diverted to assist with help needed after the next storm, Hurricane Jose, hits. It will stop in Gibraltar today to load up 260 pallets of humanitarian aid and equipment.
“They include power tools to help rebuild communities, emergency shelters, water purification kits and nappies.
Sir Michael said: “With the danger posed by Hurricane Jose, which will hit areas already affected by the storms, we are diverting a second ship to the Caribbean to bring the help needed in reconstruction after the hurricanes have passed.”