Philippine President Benigno Aquino on Monday refused to back off his country's claim over China's Huangyan Island, asking his nation to "speak with one voice" on the issue and announcing plans to upgrade military capabilities.

The Huangyan Island [file photo]??

He also said there are no simple solutions to the difficult situation, adding that the Philippine government is consulting experts and leaders to find a resolution "acceptable to all".

Although the president's remarks over Huangyan Island showed resolve and did not rule out the possibility of a diplomatic resolution, analysts said Beijing should beware of Manila's persistent drive to resort to multilateral mechanisms to complicate the situation.

"I ask for solidarity from our people regarding this issue. Let us speak with one voice," Aquino said about Huangyan Island when addressing the joint session of the Philippine Congress for the third time since his election in 2010.

This is also the first time for Aquino to give the annual "State of the Nation" speech since tensions between Beijing and Manila sharply escalated in April.

On April 10, a Philippine warship entered the island's territorial waters, sent personnel to harass Chinese fishing boats and attempted to detain Chinese fishermen. Two Chinese patrol ships in the area later came to the fishermen's rescue, and the Philippine warship left.

Beijing lodged protests in Manila over the move, which infringed on China's sovereignty, but the impasse didn't end as Manila continued to send government vessels to the Huangyan Island lagoon.

Aquino's speech on Monday showed the consistency of his stance and his position on Huangyan Island, said Yang Baoyun, an expert on Southeast Asian studies at Peking University.

Hawkish voices that demand Aquino to toughen his stance over the South China Sea issue are resonating in the Philippines, and media reports have placed high expectations over the president's speech. That's why Aquino did not dodge the island issue, said Chen Qinghong, an expert on Southeast Asian studies with the China Institutes of Contemporary International Relations.

Although Manila's rival claim over the island has initiated a series of reactions both domestically and from China, Yang said mentioning the island still helps Aquino shift focus in the context of domestic questioning over the legitimacy of his government. During his speech, the Philippine president did not insist on direct confrontation with China on the issue.

"This is not a simple situation, and there can be no simple solutions. Rest assured: We are consulting experts, every leader of our nation, our allies - even those on the other side - to find a resolution that is acceptable to all," Aquino said.

Manila has realized that it may suffer more losses if it persists in provoking China, and it has often resorted to multilateral gatherings, including the ASEAN Regional Forum Foreign Ministers' Meeting in Phnom Penh, Cambodia, this month, Chen said.

"China should be fully prepared for the latest strategy of Manila," he said.

In the speech, Aquino also announced plans for a 75 billion peso ($1.8 billion) military modernization fund to acquire a refurbished frigate, C-130 planes, utility and combat helicopters, communication equipment, rifles and mortars.

"This is not about picking a fight. This is not about bullying. This is about attaining peace. This is about our capability to defend ourselves," he said.

Yet given Manila's tough moves and remarks concerning Huangyan Island in the South China Sea, it is hard for people not to relate the military modernization bill to Manila's island rival claim, Yang said.