Defense Secretary Lloyd Austin said the missile defense system, which will be manned by U.S. service members, will arrive in Slovakia in the coming days.
The potential upgrade at a U.S. air defense base, within range of missiles in North Korea and China, has residents concerned as Seoul walks a delicate balancing act between the rival powers.
Multiple interceptors tracked and destroyed a missile carrying a dummy warhead. Advocates claim the test proves the system can provide some defense against countries such as North Korea.
The strategy, reminiscent of the Cold War-era Star Wars program, calls for new sensors in space, updated missile interceptors and advanced weapons, including lasers.
The weapons include cruise missiles, nuclear-powered underwater drones and a new hypersonic missile. Putin warned that any use of nuclear weapons against Russia or its allies would trigger a response.
From a golf course in South Korea, the U.S. can now shoot down North Korean missiles. But residents don't want a missile defense system in their backyard — and neither does China.
The THAAD missile defense system will go up in South Korea to help defend against North Korea's missile program. But it's causing a geopolitical tussle.
The missile defense system deployed to Turkey in 2013 will be withdrawn so the batteries can be updated and modernized, according to a joint U.S.-Turkey statement.