An aerial view of BRP Sierra Madre grounded at Second Thomas Shoal in the Spratly Islands
The Philippines vowed Thursday to fight China "to the last man standing", as a Chinese warship patrolled around a remote reef occupied by a handful of Filipino marines in disputed waters.
In the latest flare-up over competing claims to parts of the South China Sea, the Philippines this week denounced the "provocative and illegal presence" of the warship and a fleet of Chinese fishing vessels near Second Thomas Shoal.
After China brushed off the protest and insisted it owned the tiny reef and islets that are home to rich fishing grounds, the Philippines on Thursday ramped up the rhetoric against its much more powerful rival.
"To the last soldier standing, we will fight for what is ours," Defence Secretary Voltaire Gazmin told reporters when asked if the Philippines would bow to Chinese intimidation and pull its forces from the shoal.
However Gazmin said the Philippines was not intending to send any military reinforcements to the area, and there had been no confrontations between the two sides at the shoal since the Chinese vessels arrived early this month.
Second Thomas Shoal is one of nine Filipino-occupied islands or islets in the Spratly Islands chain.
It lies about 200 kilometres (120 miles) northwest of the Philippine island of Palawan, the nearest major landmass, and more than 1,000 kilometres from China's Hainan island.
The shoal is guarded by a handful of Filipino marines, believed to number fewer than 10, aboard a World War II-era ship that was deliberately grounded there in the late 1990s to serve as a base.
China says it has sovereign rights over nearly all of the South China Sea, even waters far away from its main landmass and approaching the coasts of Southeast Asian countries.
The Philippines, Vietnam, Malaysia, Brunei and Taiwan also claim parts of the sea, and the area has for decades been regarded as a potential trigger for major military conflict in the region.
All claimants, except Brunei, have troops stationed on various islands and atolls in the Spratlys -- the biggest archipelago in the sea -- to assert their claims.
Regional tensions have escalated in recent years as China has taken more aggressive steps to assert its claims to the sea, which is believed to sit atop vast reserves of oil and gas worth billions of dollars.
China has established a new city to oversee the area and deployed navy vessels on wide-ranging patrols of the sea, with its ships reaching as far as 80 kilometres from Malaysia's coast.
China last year also took control of Scarborough Shoal, another bountiful fishing area far closer to the Filipino landmass than China's, after a stand-off between vessels from both countries ended with the Philippines retreating.
Second Thomas Shoal is about 40 kilometres east of Mischief Reef, a Philippine-claimed outcrop that China has occupied since 1995.
Second Thomas Shoal and Mischief Reef are within the Philippines' internationally recognised exclusive economic zone.
"They should not be there. They do not have the right to be there," foreign department spokesman Raul Hernandez told AFP via text message on Thursday when asked the Chinese presence at Second Thomas Shoal.
"No one should doubt the resolve of the Filipino people to defend what is ours in that area."
President Benigno Aquino on Tuesday announced a planned $1.8-billion military upgrade to defend the country's maritime territory against "bullies".
But China's announced defence budget of $115 billion this year is nearly 100 times more than that of the Philippines.