The Philippines said Monday it would ask the United States for long-range patrol aircraft and other modern military hardware to help defend its claims to disputed waters in the South China Sea.

Defence Secretary Voltaire Gazmin said he hoped to receive the first pieces of equipment within the year, although it was not yet certain how the cash-strapped government could afford to buy the new weapons.

"We are looking at modern equipment... with the very long-range patrol aircraft and also watercraft so we can guard our territory," Gazmin told reporters.

He stressed that the Philippines was not seeking old US equipment, which it has relied on in the past, but wanted new items in the face of recent tensions with China over the South China Sea and the Spratly islands.

The United States has said it will study the list and see what kind of equipment the Philippines can afford and is capable of operating, Gazmin added.

"When you talk of new equipment you talk of operational costs. With the very limited budget that we have, we have to see if we can afford it," he said.

Gazmin said last week the Philippines was looking for new fighter aircraft, six years after retiring its Vietnam War-vintage F5 fighter jets.

Tensions in the strategic and resource-rich South China Sea have escalated in recent weeks, with the Philippines and Vietnam voicing alarm at what they say are increasingly forceful Chinese actions there.

They include accusations of Chinese forces opening fire on Filipino fishermen, shadowing an oil exploration vessel employed by a Philippine firm, and putting up structures in areas claimed by the Philippines.

The South China Sea includes the Spratlys, a chain of islands believed to sit on vast mineral resources.

Aside from the Philippines, China and Vietnam, the area is also wholly or partially claimed by Brunei, Malaysia and Taiwan.

Although the Philippines has troops on some of the Spratly islands, it has the weakest military forces in the region with no fighter aircraft and mainly World War II-vintage US ships to guard its claim.

US officials said last week that Washington was willing to provide hardware to modernise the Philippine military amid the growing territorial strains, but no details were announced.