President Ferdinand Marcos Jr. said on Thursday that the Philippines would not allow to give one square inch to any other country as Manila serves as a "frontline" for defending regional peace and stability.

Marcos Jr.'s remarks came amidst ongoing tensions in the South China Sea, where several countries, including the Philippines and China, have competing territorial claims.

The recent exchange of accusations between Beijing and Manila—including alleged incursion, shadowing, blocking, and risky maneuvers—has heightened tensions between the two nations.

In his speech to the Parliament of Australia in Canberra, Marcos Jr. compared the current situation in the South China Sea to the Philippines' experience during World War II.

"As in 1942, the Philippines now finds itself on the frontline against actions that undermine regional peace, erode regional stability, and threaten regional success," Marcos Jr. told the Australian Parliament.

"I will not allow any attempt by any foreign power to take even one square inch of our sovereign territory," Marcos Jr. added.

Marcos Jr. emphasized the importance of the Philippines' role in preserving regional and global peace, saying that the security and continued prosperity of the region – of countries like Australia — relies upon that effort.

He further highlighted the crucial role of a free and open South China Sea, calling for the international community's support in upholding the United Nations Convention on the Law of the Sea.

"We draw strength from the consistent and unequivocal support of Australia and the international community for the lawful exercise of our rights, which have been settled under international law," he said.

Before leaving for Canberra on Wednesday, Marcos Jr. called the Chinese ships' presence in the disputed waters and their interference with Philippine warships' electronic communication capabilities "worrisome"

"It's worrisome because there are two elements to that. One is that previously only the Coast Guard of China was operating in our area. Now, there's the Navy, and fishing boats have joined. So, the situation is changing," Marcos Jr. said.

The President stressed that the Philippines will keep guarding its maritime borders and helping its fishermen who fish in the disputed waters.

China on Phl's action

Meanwhile, China's Foreign Ministry spokesperson Mao Ning expressed "grave concern" over recent Philippine actions in the South China Sea, claiming Manila infringe on Beijing's sovereignty.

In 2016, an international arbitration tribunal in The Hague declared that China lacked legal standing for its claims within the Philippines' EEZ; Beijing has since rejected this ruling. The Philippines has received criticism from China for intruding on its claimed territory.

The foreign ministry official reiterated China's position on the South China Sea, which claims almost the entirety of the strategically important waterway.

"China's position on the South China Sea is consistent and clear," Ning said. "We will continue to take necessary measures to firmly safeguard our territorial sovereignty and maritime rights and interests, and keep the South China Sea peaceful and stable," she added.

The Philippines, along with Brunei, Malaysia, Taiwan, Vietnam, and Indonesia, all have overlapping claims with China in the South China Sea. The region is believed to be rich in natural resources and is a crucial shipping lane.