Philippines' Marcos says he remains firm in defending sovereignty

Philippine President Ferdinand Marcos Jr told the Australian parliament on Thursday he would not allow any foreign power to take "one square inch" of the country's territory, and that Manila was firm in defending its sovereignty.

Australia and the Philippines began their first joint sea and air patrols in the South China Sea in November, aimed at countering an increasingly assertive China, which claims the entire sea as its own.

"I will not allow any attempt by any foreign power to take even one square inch of our sovereign territory," Marcos said in the address.

The South China Sea is a conduit for more than $3 trillion worth of ship-borne commerce each year, and is a major source of tension between the Philippines and neighbour China.

Manila accuses Beijing of committing aggressive acts inside its exclusive economic zone (EEZ); an international arbitration tribunal in the Hague said in 2016 that China's claims inside the Philippines' EEZ had no legal basis - a decision Beijing has rejected. China has chided the Philippines for encroaching on what it says is its territory.

Protecting the area is important to global stability, Marcos said on Thursday.

"The protection of the South China Sea as a vital, critical global artery is crucial to the preservation of regional peace and, I dare say, of global peace," he said. "We have an abiding interest in keeping our seas free and open, and in ensuring unimpeded passage and freedom of navigation."

Marcos is in Australia on an official visit, before he attends a special summit of the Association of Southeast Asian Nations (ASEAN) in Melbourne next week.