China and the Philippines face a new challenge to their diplomatic ties after Manila filed a mild protest before the Chinese Embassy last month over Beijing's reported military buildup on the islands and reefs in the contested Spratly Islands in the South China Sea.

Analysts said on Tuesday that the improved relationship between the two countries is being tested by rising tensions over Beijing's reported militarization of islands in the disputed waters as well as US President Donald Trump's challenge to Beijing's influence in Asia.

Like Us on Facebook

Beijing has reportedly deployed anti-missile systems and high-powered weaponry to its controlled islands and has built airstrips large enough to accommodate military jets and cargo planes.

The Philippines' conflict with China coupled with Trump's latest attacks on Beijing have put Philippine President Rodrigo Duterte in a situation where he has to balance power without giving up his country's sovereignty claims to the disputed waters, analysts said.

$24 Billion Investment Package

Barely a month after assuming the presidency, Duterte has set aside an arbitration court ruling favoring Manila's claims to the disputed waterway in order to negotiate with Beijing on other aspects of their relations such as investment and economic cooperation.

In October, Duterte made his first official state visit to Beijing and brought home a $24 billion aid and investment package, including soft loans and financial assistance.

This week, a Philippine delegation flew to Beijing to hammer out the final details of a $15 billion investment package signed by Duterte and Chinese President Xi Jinping during the former's visit to the mainland in October last year.

Note Verbale

However, two months after the groundbreaking visit, Manila has filed a mild protest, a note verbale, to the Chinese embassy over Beijing's reported buildup of military facilities on the contested Spratly Islands.

"It kind of underlines the fact the Spratly Islands are a serious national interest issue for the Philippines and that despite the element of friendly relations after the Duterte visit to Beijing, it doesn't seem as simple as just the issue has been traded off for better Chinese relations and China can anticipate getting everything it wanted after all," said Douglas Guilfoyle, associate international law professor at Monash University in Australia.

Ernesto Abella, the Philippine presidential spokesman, said Manila would continue to uphold its sovereignty to the contested islands in the strategic waterway and find ways to improve its relations with Beijing at the same time.

Last year, an international tribunal ruled that China has no legal basis for its massive territorial claims in the South China Sea. The court stated that Beijing's activities had violated international law and the Philippines' rights to exploit its resources within its exclusive economic zone.

China rejected the ruling saying it was "illegal" and "null and void."

Duterte has since shelved the ruling saying he would discuss the verdict with Beijing once China accepts the court's decision.

To date, the Philippines exercises control over nine features consisting of islands, reefs, and shoals in the Spratly Islands while China has control over seven territories.

TagsSino-Philippine relations, South China Sea, spratly islands, President Xi Jinping, economic cooperation, mild protest, President Rodrigo Duterte, Philippines, china