The Philippines has asked a United Nations-backed tribunal to void China’s claim over almost the entire South China Sea. It expects a decision this year.
China did not participate in the arbitration hearings at The Hague as it maintained that sea disputes should be resolved bilaterally.
"Win or lose, we will abide by the rule of law and we expect China to do the same," Del Rosario said.
Hammond said Britain would not take sides on the dispute but appealed to claimants to resolve their differences under international law.
"We recognise the tribunal and we will recognise the decision of the tribunal," Hammond said.
Malaysia, Brunei and Taiwan also have competing claims in the South China Sea, which hosts vital shipping lanes over vast oil and gas reserves.