Philippine

"The unoccupied, which are ours, let's live on it," Mr Duterte told reporters during a visit to a military base in Palawan.

The move is expected to anger China, which claims several contested shoals, islets and reefs in the territory.

China has been constructing artificial islands in the area for years.

While the Philippines occupies nine features in the South China Sea, including a World War Two-era transport ship, Beijing claims almost all of the territory. It is unlikely to welcome an increased military presence from the Philippines.

Jurgen Kantner was abducted from his yacht off Malaysia's Sabah state in November. His companion Sabine Merz's body was later found on the boat.

A deadline for a 30m peso (£483,000; $600,000) ransom expired on Sunday.

Mr Kantner, 70, and Ms Merz had been abducted before. They were held for 52 days in 2008 by Somali pirates and were released after a ransom was paid.

The video, reported by the SITE militancy-monitoring group, shows Mr Kantner being killed by a knife-wielding man.

Government envoy Jesus Dureza confirmed the killing.