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US President Joe Biden and President Ferdinand Marcos Jr. of the Philippines
CNN  — 

President Joe Biden welcomed President Ferdinand Marcos Jr. of the Philippines to the White House on Monday as part of continued efforts to strengthen security and economic relations in the region amid concerns over an increasingly assertive China.

Sitting in the Oval Office at the start of their talks, Biden said the US “remains ironclad in our commitment to the defense of the Philippines, including the South China Sea.”

“We’re going to continue to support the Philippines military’s modernization goals,” Biden told the visiting leader, pledging the two nations “not only share a strong partnership – we share a deep friendship, one that has been enriched by millions of Filipino Americans in the communities all across the United States.”

Speaking afterward, Marcos told Biden their two countries must “find ways to strengthen our alliances and partnership,” saying ongoing tensions in Asia make for the world’s most complicated geopolitical situation.

The meeting was a show of solidarity meant as a message to China that America remains committed to its allies in the neighborhood. A 1951 mutual defense treaty between the US and the Philippines – the oldest such US pact in the Asia-Pacific – stipulates both sides would help defend each other if either were attacked by a third party.

The invitation to the White House was also a sign of Biden’s intent on reestablishing strong ties with Manila after they had frayed under former President Rodrigo Duterte, who sought closer relations with China.

A White House fact sheet released Monday described new steps and initiatives the two allies are committing to, including a new set of bilateral defense guidelines to strengthen the alliance and the transfer of US hardware – including three C-130 aircraft and additional coastal patrol vessels – to support efforts to modernize Manila’s armed forces.

Other initiatives include a US trade mission to the Philippines later this year and $3 billion in public and private financing to buttress infrastructure for critical minerals, according to the fact sheet.

Marcos’ visit caps a busy month in bilateral engagements as defense ties between the two nations have expanded, raising alarms in Beijing. Thousands of American and Filipino troops have taken part in joint exercises over the past three weeks. And the US recently hosted two top diplomats from the Philippines for talks during which both sides agreed to complete a roadmap for Washington to provide security assistance to its regional ally over the next five to 10 years.

Last year, the US granted $100 million to boost the Southeast Asian country’s defense capabilities and military modernization. It also plans to allocate $100 million for the improvement of military bases to which the US has access under the 2014 Enhanced Defense Cooperation Agreement, or EDCA.

In February, the Philippines granted new rights to the US military to add four bases to the five originally covered under the EDCA. The new facilities include three on the main island of Luzon, close to Taiwan, and one in Palawan province in the South China Sea.

China, which remains one of the Philippines’ top trading partners, has grown increasingly outspoken about the burgeoning US-Filipino defense ties.

Beijing’s ambassador in Manila, Huang Xilian, accused the Philippines last month of “stoking the fire” of regional tensions by offering expanded military base access to the US, saying that the goal was to interfere in China’s affairs with Taiwan.

China’s ruling Communist Party has never controlled Taiwan but claims the self-ruled island democracy as its own and has repeatedly refused to rule out taking it by force – a threat that Manila perceives as reason to ramp up its guard with help from Washington.

A spokesperson for Marcos’ National Security Council responded to Huang’s remarks by saying that “the Philippines has no intention of interfering in the Taiwan issue.”

Marcos, who is known almost universally in the Philippines by the nickname Bongbong, is the son of longtime dictator Ferdinand Marcos Sr., whose regime was supported by the United States. As senator, Biden was outspoken in opposition to the American backing of Marcos Sr.

This story has been updated with additional developments.

CNN’s Brad Lendon and Shawna Mizelle contributed to this report.