Visitors walk on the bow of the guided missile cruiser USS Shiloh while anchored at Subic Bay, a former US naval base in the Philippines, on May 30, 2015, as part of an ongoing US military patrol in the South China Sea amid rising tensions over China's building of artificial islands over reefs in the sea that are also claimed by other neighbours including the Philippines, a US military ally. US Defence Secretary Ashton Carter, speaking at a high-level security conference in Singapore, called on May 30, for an "immediate and lasting halt" to reclamation works in disputed South China Sea waters. AFP PHOTO / Robert Gonzaga