Biden will reaffirm Washington's "ironclad commitment to the defense of the Philippines, and the leaders will discuss efforts to strengthen the longstanding US-Philippines alliance," White House Press Secretary Karine Jean-Pierre said.

The White House announcement comes a week after the largest-ever joint US-Philippines military exercises in the disputed South China Sea in the face of China's growing assertiveness in the region, particularly over Taiwan, the self-governing island it claims as its own.

Last week, the US secretaries of Defense and State met with their Philippine counterparts in Washington in a high-level summit, days after the US gained greater military access in the Philippines.

Defense Secretary Lloyd Austin warned of "a troubling increase in coercion and dangerous operational behavior" in the South China Sea, an apparent reference to a three-day Chinese military exercise that simulated a blockage and targeted strikes against Taiwan.

The White House statement said Biden and Marcos would discuss other matters including economic cooperation, clean energy and respect for human rights.

"The two leaders will also discuss regional matters and coordinate on efforts to uphold international law and promote a free and open Indo-Pacific," the statement said.

Manila earlier this month announced the locations of four more military bases it is allowing the US military to use on top of the five agreed on under the 2014 Enhanced Defense Cooperation Agreement, known as EDCA.

The deal allows US troops to rotate through and store defense equipment and supplies.

China warned last week the expanded military deal could endanger regional peace, and accused Washington of a "zero-sum mentality."

The four additional bases include sites near the hotly disputed South China Sea and another not far from Taiwan.

Marcos said China's reaction over the expanded military deal was "not surprising," but assured them the Philippines is only shoring up its territorial defense.

"We will not allow our bases to be used for any offensive actions. This is only aimed at helping the Philippines whenever we need help," Marcos told reporters.

"If no one is attacking us, they need not worry because we will not fight them."

US-Philippines ties stalled under former president Rodrigo Duterte, who favored closer ties with China.

But Marcos, who succeeded Duterte in June, has adopted a more US-friendly foreign policy.