The U.S. defense secretary expressed dissatisfaction at the poor living environment for soldiers at the Terminal High-Altitude Area Defense battery base in Seongju, North Gyeongsang Province when he visited South Korea last week, sources said Thursday.

In a meeting with Defense Minister Suh Wook, Lloyd Austin blasted the neglect of the THAAD base as "unacceptable" and called for improvement of the situation.

The U.S. Forces Korea deployed the THAAD equipment in April 2017 to respond to the ballistic missile threat from North Korea. But there has been practically no progress in building facilities for personnel there over the last four years as civilian protesters block the only access road to the former golf course.

Korea found itself in hot water over the deployment with China, which is paranoid about the THAAD battery’s powerful radar, and had to endure a yearlong unofficial Chinese boycott.

Police block protesters to let vehicles into the Terminal High-Altitude Area Defense battery base in Seongju, North Gyeongsang Province on Jan. 22.
Police block protesters to let vehicles into the Terminal High-Altitude Area Defense battery base in Seongju, North Gyeongsang Province on Jan. 22.

Some 400 Korean and American troops are still housed in the old golf clubhouse and shipping containers, and basic supplies for troops and fuel have to be airlifted in.

Soldiers have sometimes have to make do with combat rations, though protesters have recently started to let food trucks through. The road to the base is under around-the-clock surveillance by a "situation room" set up by the protesters.

Austin also asked Suh to ensure better environments at the training facilities of the Rodriguez live-fire range in Pocheon, Gyeonggi Province and the Suseong firing range in Pohang, North Gyeongsang Province, a Defense Ministry spokesman said.

"We're looking for ways to improve poor living conditions for the troops and find a solution with local residents," the spokesman added.