FILE PHOTO: A Terminal High Altitude Area Defense (THAAD) interceptor is launched during a successful intercept test, in this undated handout photo provided by the U.S. Department of Defense, Missile Defense Agency. U.S. Department of Defense, Missile Defense Agency/Handout via Reuters/File Photo

WASHINGTON (Reuters) - A U.S. anti-missile defense system being deployed to South Korea will have initial operational capability “very soon,” a Pentagon spokesman told reporters on Friday.

“It is moving very quickly, it will (have) initial operational capability very soon,” Pentagon spokesman Captain Jeff Davis said.

In an interview, Trump told Reuters on Thursday he wants South Korea to pay for the $1 billion Terminal High Altitude Area Defense (THAAD) system.