Puerto Princesa, Philippines - US Vice President Kamala Harris on Tuesday visited a Philippine island near waters claimed by China, vowing to rally against "unlawful and irresponsible behavior" to protect communities, their livelihood, and the environment.

Harris is the highest-ranking US official to ever visit the western Philippine province of Palawan near the disputed South China Sea.

She met community leaders and residents from the fishing village of Tagburos in Puerto Princesa City, who told her about how the fishing industry not only provides food for residents but also "serves as the economic lifeblood of the island."

She then toured the coastguard vessel MV Teresa Magbanua, which recently hosted a training activity attended by the Philippine coastguard and US service members.

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"I am here in Palawan to underscore the importance of our partnership in order to create economic opportunities, protect coastal ecosystems, maintain peace and stability, and uphold international rules and norms here in the South China Sea and around the world," she said after receiving a briefing on maritime operations from the coastguard.

"To uphold international rules and norms is to support the lives and livelihoods of people throughout the region," she added.

Harris said the vitality of communities like Tagburos was at risk when "foreign vessels enter Philippine waters and illegally deplete the fishing stock, when they harass and intimidate local fishers, when they pollute the ocean and destroy the marine ecosystem."

She added that the United States also has a "profound stake" in the future of the region, saying, "America’s prosperity relies on the billions of dollars that flow through these waters every day."

"As an ally, the United States stands with the Philippines in the face of intimidation and coercion in the South China Sea," she said.

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"We will continue to rally our allies and partners against unlawful and irresponsible behavior, when the international rules-based order is threatened somewhere, it is threatened everywhere."

On Sunday, a Chinese coastguard vessel blocked a Philippine Navy team as they towed unidentified metallic debris – the remains of a Chinese rocket – recovered near Pagasa Island and forcibly took the item, military officials said.

The Chinese embassy said the reports on the incident were "inconsistent with facts," the wreckage was turned over to their coastguard after "friendly consultation with the Philippine side."

The Philippines and China are embroiled in a territorial dispute due to overlapping claims in the South China Sea, where Beijing has taken over areas and built artificial islands with military-capable facilities.

Beijing has ignored a 2016 ruling by an international arbitration court that it has no legal or historical basis for its expansive claims in the area. The ruling was made in relation to a case filed by the Phillippines.

Harris reiterated the US support for the ruling, saying, "The tribunal’s decision is legally binding and must be respected."

Aside from the Philippines, Vietnam, Malaysia, Brunei, and Taiwan also have overlapping claims to the area, which is believed to be rich in natural resources.

On Monday, Harris assured President Ferdinand Marcos Jr. of the US' "unwavering commitment" to come to the Philippines' defense in case of an armed attack against it in the South China Sea.