The United States and the Philippines on Thursday announced plans to expand America’s military presence in the Southeast Asian nation, with access to four more bases as they seek to deter China’s increasingly aggressive actions toward Taiwan and in the disputed South China Sea.

The agreement was reached as US Defense Secretary Lloyd Austin was in the country for talks about deploying US forces and weapons in more Philippine military camps.

In a joint announcement by the Philippines and the US, the two said they had decided to accelerate the full implementation of their so-called Enhanced Defense Cooperation Agreement, which aims to support combined training, exercises and interoperability.

As part of the agreement, the US has allocated $82 million toward infrastructure improvements at five current EDCA sites, and expand its military presence to four new sites in “strategic areas of the country,” according to the statement.

Austin arrived in the Philippines on Tuesday from South Korea, where he said the US would increase its deployment of advance weapons such as fighter jets and bombers to the Korean Peninsula to bolster joint training with South Korean forces in response to North Korea’s growing nuclear threat.

In the Philippines, Washington’s oldest treaty ally in Asia and a key front in the US battle against terrorism, Austin visited southern Zamboanga city and met Filipino generals and a small contingent of US counterterrorism forces based in a local military camp, regional Philippine military commander Lt Gen Roy Galido said.

The more than 100 US military personnel have provided intelligence and combat advice for years to Filipino troops battling a decades-long Muslim insurgency, which has considerably eased but remains a key threat.

More recently, US forces have intensified and broadened joint training focusing on combat readiness and disaster response with Filipino troops on the nation’s western coast, which faces the South China Sea, and in its northern Luzon region across the sea from the Taiwan Strait.

American forces were granted access to five Philippine military camps, where they could rotate indefinitely under the 2014 EDCA defense pact.

In October, the US sought access for a larger number of its forces and weapons in an additional five military camps, mostly in the north. That request would be high on the agenda in Austin’s meetings, according to Philippine officials.