The United States has announced that it is identifying more sites for the implementation of its Enhanced Defense Cooperation Agreement (EDCA) with the Philippines.

A senior White House official made the pronouncement on Sunday night (Manila time), adding that the US is now engaged with Philippine officials for a mutual decision on the matter.

"So we're working on expanding the program. But the precise number of locations and where those locations will be is not for now," he said in an online briefing.

EDCA is an agreement between the US and the Philippines that provides a legal basis for American and Filipino service members to undertake security cooperation exercises, pursue joint and combined military training activities and rapidly respond to humanitarian assistance and relief efforts from agreed locations in the Philippines, on a rotational basis.

EDCA sites have been used, among other functions, by US and Philippine forces during Kamandag and Balikatan military exercises.

There are currently five existing locations in Pampanga, Nueva Ecija, Cagayan de Oro, Cebu and Palawan.

US Vice President Kamala Harris' visit to the Philippines, which started Sunday, is expected to yield a deal for the new EDCA sites, according to the official.

"As an outcome of the Vice President's visit to Manila, we're strengthening our security cooperation related to the EDCA," he said.

So far, US has allocated over $82 million towards EDCA implementation to eventually complete its 21 total projects that will enable the two countries "build lasting security infrastructure to promote long-term modernization, building a credible mutual defense posture, maintain humanitarian assistance and disaster relief capabilities and enhance the strength of the alliance," a fact sheet from the White House read.

Military cooperation between the US and the Philippines was reinforced under President Marcos' administration following the reiteration of the US commitment to honor the Mutual Defense Treaty (MDT) it has had with the country.