This file photo shows activists holding a protest in front of the Chinese Consular Office in Manila, last month, demanding the Chinese government to immediately pull out from Scarborough Shoal

The Philippines said Wednesday the United States had pledged to protect it from attacks in the South China Sea, a day after China issued a warning over a territorial row in the waters.

Defence Secretary Voltaire Gazmin said he had received the assurances during talks in Washington last week in which the Philippines' increasingly tense dispute with China over rival claims to a shoal in the sea were discussed.

Gazmin said US Secretary of State Hillary Clinton and Defence Secretary Leon Panetta stressed they were not taking sides in the dispute, but they assured the Philippines the United States would honour a 1951 mutual defence treaty.

"It includes armed attack... (on) island territories in the Pacific (region)," Gazmin said, citing conditions for the allies coming to each other's aid.

In answer to a question about the dispute with China over Scarborough Shoal, Gazmin said he had interpreted remarks by Clinton to mean the United States would protect the Philippines from any attack in the South China Sea.

"Overall, with these statements, they cover our problem in the West Philippine Sea," he said, using the Philippine name for the waters.

China and the Philippines have had vessels stationed at Scarborough Shoal for more than a month in an effort to assert their sovereignty over the area.

China claims virtually all of the South China Sea as its own, even waters close to the coasts of other Asian countries.

The Philippines insists it has sovereignty over the shoal because it falls within its 200-nautical-mile exclusive economic zone.

The shoal sits about 230 kilometres (140 miles) from the Philippines' main island of Luzon and 1,200 kilometres northwest from the nearest major Chinese land mass, according to Filipino navy maps.

Taiwan, Brunei, Vietnam and Malaysia also claim parts of the South China, which is believed to sit atop vast oil and gas resources, making the area one of Asia's potential military flashpoints.

China warned on Tuesday it was prepared for "any escalation" in the dispute with the Philippines, which followed an editorial in a newspaper run by the ruling Communist Party calling for a small-scale war to end the stand-off.

Foreign Secretary Albert del Rosario also issued a statement on Wednesday saying that Clinton and Panetta had reaffirmed during the Washington talks US commitment to the mutual defence treaty with the Philippines.