The deployment of a key missile defense system to South Korea is “going to happen,” even if the Chinese government objects to it, Defense Secretary Ashton Carter said Friday.

The U.S. and South Korean governments began talks earlier this year on the potential placement of the system—the Terminal High-Altitude Area Defense (THAAD) system made by Lockheed Martin [LMT]—on the Korean peninsula. U.S. officials have argued that THAAD, which intercepts missiles inside and outside the Earth’s atmosphere, is a necessary deterrent against North Korean ballistic missile threats, but China has raised its own concerns with the potential deployment.

A Terminal High Altitude Area Defense (THAAD) battery deploys a missile. Photo: Lockheed Martin.
A Terminal High Altitude Area Defense (THAAD) battery deploys a missile. Photo: Lockheed Martin.

The United States and China have been unsuccessful in getting North Korea to stop provocative actions, which includes recent ballistic missile launches and a recent nuclear test. In response, the Defense Department is considering changes to its missile defense posture, including the deployment of THAAD, Carter said.

No official agreement has been finalized, but “it’s going to happen,” he said at the Council on Foreign Relations in New York.. “It’s a necessary thing.  It is between us and South Korea. It’s part of protecting our own forces on the Korean Peninsula and protecting South Korea.  It has nothing to do with the Chinese.”

“We need to defend our own allies and we’re going to do that,” he added.

Carter said it would be “illogical” for the Chinese government to view the deployment of THAAD as a blow to Chinese-South Korean relations. “We’re actually quite encouraged to see the Republic of Korea and China strengthening their own relationship,” he said.

The United States would also like to see China play more of an active role with North Korea. In the past, China has held “the greatest leverage” over North Korea because of its economic and military ties as well as its close geographic location, Carter said.

‘”I do wish the Chinese would work with us or, really, work bilaterally with North Korea more effectively,” he said, noting that “although it is easy to say that, dealing with North Korea—for anybody—is a challenge.”

U.S. military officials in the Asia-Pacific region—including Army Gen. Curtis M. Scaparrotti, commander of U.S. forces in Korea, and Adm. Harry Harris, head of Pacific Command—have strenuously supported a THAAD deployment to the Korean peninsula.