“An armed attack on Philippine armed forces, public vessels and aircraft will invoke US mutual defense commitments under that treaty,” Blinken told a news conference.
“The Philippines is an irreplaceable friend, partner, and ally to the United States.”
Blinken was the most senior US official to meet new President Ferdinand Marcos Jnr., the son of the late strongman who Washington helped to flee into exile in Hawaii during a 1986 “people power” uprising that ended his two-decade rule.
In opening remarks to Blinken, Marcos sought to downplay the diplomatic flare-up over Taiwan and said he believed Pelosi’s trip “did not raise the intensity” of a situation that was already volatile.
“We have been at that level for a good while, but we have sort of got used to the idea,” Marcos said.
The Philippines is a fulcrum of the geopolitical rivalry between the US and China and Marcos faces a tricky challenge in balancing ties between the two major powers.
US-Philippines ties were shaken by predecessor Rodrigo Duterte’s overtures towards China, his famous anti-US rhetoric and threats to downgrade their military ties.
On Saturday, Philippine Foreign Secretary Enrique Manalo said President Joe Biden had invited Marcos to Washington, and both sides were working on a suitable date.
Marcos has not been to the US in more than a decade, due largely to a contempt of court order for his refusal to cooperate with a Hawaii court, which in 1995 ordered the Marcos family to return $2 billion of missing state wealth to victims of abuses by the state under his father’s rule.
Marcos Jnr. and mother, Imelda, also face a $353 million fine.
The US embassy in Manila has said heads of state have diplomatic immunity.
Manalo said Washington was an important ally, but concerning nearby Taiwan he told Blinken the Philippines “looks at the big powers to help calm the waters.”
“We can ill afford any further escalation of tensions,” he said.