Philippine President Benigno Aquino has made a veiled comparison between China's activities in the South China Sea and Nazi Germany's expansionism before the Second World War, echoing similar remarks he made last year that outraged Beijing.

Mr Aquino, who is expected to agree beefed up defence ties with Japan when he meets Prime Minister Shinzo Abe on Thursday, also urged Beijing to rethink its land reclamation projects in the disputed waters.

China has been taking an increasingly assertive posture in recent years in the South China Sea, building artificial islands in areas where Manila and other Southeast Asian countries have rival claims.

Asked about Washington's strategic "rebalance" to Asia and China's maritime moves, Mr Aquino suggested the US role was key, and alluded to Nazi Germany's territorial expansion before the Second World War and Western appeasement.

"If there was a vacuum, if the United States, which is the superpower, says 'We are not interested', perhaps there is no brake to ambitions of other countries," he said.

Recalling documentaries on Germany's expansionism before the war, Mr Aquino added: "The commentators on these documentaries were saying, 'If somebody said stop to (Adolf) Hitler at that point in time, or to Germany at that time, could we have avoided World War Two?'

"So, I say again, America's rebalancing sends a definite signal that we are all supposed to be living under norms that we agreed upon."

China's Foreign Ministry expressed shock at the "outrageous and unreasonable" remarks by Mr Aquino, which were similar to ones he made last year.

"I once more seriously warn certain people in the Philippines to cast aside their illusions and repent, stop provocations and instigations, and return to the correct path of using bilateral channels to talk and resolve this dispute," ministry spokeswoman Hua Chunying said.