The Philippines said Tuesday it was hoping to help secure its energy future by developing a natural gas field in an area of the South China Sea also claimed by China.

The comments come amid high tension with China over territorial disputes in the South China Sea and with Manila and Beijing locked in a standoff over the Scarborough Shoal.

Energy Secretary Rene Almendras expressed optimism that Reed Bank, which lies about 148 kilometres (92 miles) from the Philippine island of Palawan, would yield massive amounts of natural gas.

"Reading the statements (of higher reserves on the Reed Bank), I cannot help but smile and be happy because hopefully it's true, and its big resources will help us face the need for energy in the future," he told ABS-CBN television.

He was referring to reports that Philippine-owned company, Forum Energy, had discovered possibly the country's biggest natural gas reserves there.

Last year the Philippines accused Chinese vessels of harassing an exploration vessel off Reed Bank, and Manila has repeatedly accused China of aggressive actions in disputed waters.

Manila and Beijing have been locked in a standoff over Scarborough, a group of islands in the South China Sea, since Chinese vessels blocked Philippine attempts to arrest eight Chinese fishing boats' crews earlier this month.

Two Chinese patrol ships in the area were still facing off Tuesday against a Philippine coast guard vessel, about 230 kilometres west of the main Philippine island of Luzon, officials said.

The Philippines has said both Reed Bank and Scarborough Shoal are well within its maritime territory but China, which claims almost all of the South China Sea, disputes this.

In a speech before Congress last year, Philippine President Benigno Aquino vowed to defend the country's claim to Reed Bank.

Forum Energy is to update its estimate of the Reed Bank reserves later this week after processing new exploration data, its majority-owner Philex Petroleum Corp. disclosed in Manila.

"This report is expected to show an improvement in the resources previously known," Philex told the Philippine Stock Exchange.

Its previous estimate for Reed Bank was 96.28 trillion litres (3.4 trillion cubic feet) of natural gas.

The prospect is located near Malampaya, the Philippines' largest currently known gas field, which is operated by Royal Dutch Shell.