The Chinese coast guard has "forcefully" retrieved rocket debris that a Philippine naval boat was towing to a nearby island, Philippine authorities said Monday, in the latest encounter in the disputed South China Sea.

The Philippine Armed Forces Western Command said the incident happened Sunday morning, hours before U.S. Vice President Kamala Harris arrived in Manila, as it received a report of a floating object, which resembled debris from a Long March 5B rocket that China launched in late October.

Philippine President Ferdinand Marcos Jr. (L) greets U.S. Vice President Kamala Harris at the presidential Malacanang Palace in Manila on Nov. 21, 2022. (Kyodo)

The debris was found about 730 meters west of the Philippine-occupied island of Thitu, a maritime feature in the South China Sea, where Beijing's claims over vast swaths of territory have stirred up tensions with several regional neighbors, including Vietnam and Malaysia.

As the Philippine Navy began towing the debris back to the island, a Chinese Coast Guard rigid hull inflatable boat approached and twice attempted to block the vessel's way before the boat's crew took the object by cutting the towing line, according to the navy.

Philippine President Ferdinand Marcos Jr. met with Harris on her three-day visit to the Southeast Asian country on Monday.

Harris said at the outset of the meeting that the alliance between the United States and the Philippines is based on "mutual concerns," referring to both countries as "proud members of the Indo-Pacific."

"In particular, as it relates to the Philippines, I will say that we must reiterate always that we stand with you in defense, and armed attack on the Philippines' armed forces, public vessels, or aircraft in the South China Sea would invoke U.S. defense commitments. And that is an unwavering commitment that we have with the Philippines," Harris told Marcos.

According to the White House, they discussed a number of issues with Harris reiterating U.S. interests in maintaining peace and stability in the South China Sea, as well as Washington's support for the Philippines in upholding an international rules-based maritime order.

Harris is set to visit Palawan on Tuesday, becoming the highest-ranking U.S. official to set foot on the Philippine island that is close to contested areas in the sea.

Also Monday, Philippine Space Agency Director General Joel Joseph Marciano said the agency has yet to determine whether the debris was part of the Chinese Long March 5B rocket launched on Oct.31 or the Long March 7, which lifted off on Nov. 12.

The debris fell within Philippine maritime territory, Marciano stressed in an interview with Kyodo News, describing the China Coast Guard's severing of the Philippine Navy's tow line as "unfriendly."

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