United States President Barack Obama on Wednesday (Nov 18) expressed firm backing for Philippine actions to assert its claims over parts of the South China Sea.
He said: "We fully support a process in which, through international law, these issues are resolved."
In a joint news conference with Philippine President Benigno Aquino, Mr Obama said the US has a "rock-solid commitment" to the Philippines, and called Mr Aquino as a "valuable and trusted friend".
He said he discussed with Mr Aquino, on the sidelines of the ongoing summit of Pacific-rim leaders, disputes over the South China Sea and the "importance of keeping freedom of navigation" in this vital sea lane, through which US$5 trillion (S$7.1 trillion) in ship-borne trade passes every year.
"We're not claimants ourselves, but we fully support a process in which, through international law, these issues are resolved," said Mr Obama.
In a 4,000-page plea filed with an international arbitration court in The Hague, the Philippines is accusing China of violating international laws by claiming areas that are 1,611km away from its borders, even waters that are 1,611km from its coasts and nearer its smaller neighbours.
Tensions have escalated after China stepped up its land reclamation efforts in the Spratly archipelago, where it has so far created islands with airstrips and garrisons on seven reefs it occupies.
The US has sent a guided missile destroyer and a B-52 bomber to these islands to assert "freedom of navigation" in the area.
Mr Obama said the US was also looking forward to setting in motion a 10-year US-Philippine defence pact signed the last time he was in Manila last year.
The Supreme Court is set to rule on the validity of that deal next month.
Mr Obama said the pact would "bring our militaries even closer together".