The United States on Saturday called for an "immediate and lasting halt" to reclamation works in disputed waters in the South China Sea, saying China's behaviour in the area was "out of step" with international norms.

"First, we want a peaceful resolution of all disputes. To that end, there should be an immediate and lasting halt to land reclamation by all claimants," US Defense Secretary Ashton Carter told a high-level security conference in Singapore.

"We also oppose any further militarisation of disputed features," he said.

Carter added that "with its actions in the South China Sea, China is out of step with both the international rules and norms".