WASHINGTON, May 4 (Reuters) - Philippines President Ferdinand Marcos Jr said on Thursday that granting U.S. access to Philippine military bases was a defensive step that would be "useful" if China attacked Taiwan.

Marcos, speaking at the end of a four-day visit to Washington that included a summit with President Joe Biden and an agreement to update the countries' nearly 72-year defensive alliance, did not respond directly when asked whether the United States could place weapons at the bases if China attacked Taiwan.

Marcos told Reuters the Enhanced Defense Cooperation Agreement (EDCA) reached with the United States in 2014 was originally conceived to improve disaster responses.

"Now there's an additional aspect to it," he said. "And that is … tensions across the Taiwan Straits seem to be continuing to increase. Then the safety of our Filipino nationals in Taiwan becomes of primordial importance."

"And so these EDCA sites will also prove to be useful for us should that terrible occurrence come about," he added, referring to an invasion of Taiwan.

A February agreement to allow the U.S. to use four additional Philippines military bases is highly sensitive for Manila, which wants closer military ties to the United States without alarming China, its largest trading partner.

China has said that decision was "stoking the fire" of regional tension.

Marcos said Washington "has not proposed any kind of action for the Philippines in terms of taking part in the defense of Taiwan."

"It's of a defensive nature and maybe a civil-defense nature, when I talk about the disasters and the evacuation of our Filipino nationals," he said.