US President Joe Biden heads to a trilateral meeting with Japanese Prime Minister Fumio Kishida (R) and Filipino President Ferdinand Marcos Jr. (L) at the White House in Washington, DC, on April 11, 2024. Andrew Caballero-Reynolds, AFP 

US President Joe Biden pledged Thursday to defend the Philippines from any attack in the South China Sea, as he hosted the first joint summit with Tokyo and Manila amid growing tensions with Beijing.

Biden's three-way meeting with Philippines President Ferdinand Marcos and Japanese Prime Minister Fumio Kishida follows repeated confrontations between Chinese and Philippine vessels in the disputed waterway.

"The United States defense commitments to Japan and to the Philippines are ironclad," Biden said as he opened the meeting in the East Room of the White House.

"Any attack on Philippine aircraft, vessels or armed forces in the South China Sea would invoke our mutual defense treaty."

China claims almost the entirety of the South China Sea, brushing aside competing claims from several Southeast Asian nations including the Philippines, as well as an international ruling that has declared its stance baseless.

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The joint summit came a day after Biden hosted a lavish state visit for Japan's Kishida during which he unveiled a historic upgrade in defense ties aimed at countering a resurgent China.

Kishida gave a joint address to Congress on Thursday in which he urged Americans to overcome "self-doubt" about their role as a global power.

Warning of risks from the rise of China, Kishida said that Japan -- stripped of its right to a military after World War II -- was determined to do more to share responsibility with its ally the United States.

At the trilateral summit, the United States, Japan and the Philippines are expected to announce new joint naval exercises along with Australia, similar to drills they had in the region at the weekend, officials said.

They are also set to unveil new economic cooperation measures.

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'SMEARED' 

Biden also held separate talks with Marcos, who is seen as closer to Washington than his more authoritarian and China-leaning predecessor Rodrigo Duterte.

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China hit back, saying the United States and Japan had "smeared" its reputation during Kishida's state visit.

Beijing foreign ministry spokeswoman Mao Ning said Washington and Tokyo had "attacked China on Taiwan and maritime issues, grossly interfered in China's internal affairs, and seriously violated the basic norms governing international relations."

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The United States has a mutual defense pact with Manila but there are fears it could be put to the test, with tensions becoming particularly acute around the Second Thomas Shoal, a remote reef in the Spratly Islands.

The trilateral summit is part of Biden's efforts to seal alliances with like-minded nations in a region that both Beijing and Washington consider part of their geopolitical backyard.

Japan and the Philippines are the latest Asia-Pacific allies to be hosted by Biden, who was joined by Kishida and South Korean President Yoon Suk Yeol at Camp David in August.

Biden has also moved to manage tensions with China, holding a two-hour phone call with President Xi Jinping last week following a face-to-face meeting in San Francisco in November.

On Wednesday Biden said the major upgrade in defense ties with Japan was "purely defensive" and "not aimed at any one nation or a threat to the region."

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© Agence France-Presse