US has started to deploy major components of Terminal High-Altitude Area Defense (Thaad) Missile System at its site in South Korea.
On Wednesday, six trailers carrying parts of the THAAD system arrived at a former golf course in the county of Seongju in the country's southern region, Yonhap news agency and YTN television reported today.
Television footage showed military trailers carrying equipment, including what appeared to be launch canisters.
The canisters are being taken into the planned THAAD battery site which is about 250 kilometers (155 miles) south of Seoul.
The full-scale deployment has been started and it would be completed by the end of the year, South Korea's Defense Ministry confirmed.
"South Korea and the United States have been working to secure an early operational capability of the THAAD system in response to North Korea's advancing nuclear and missile threat," the Defense Ministry said.
The US and South Korea are deploying the missile system in response to the ongoing development of North Korea's ballistic missile program, which has continued despite multiple sets of United Nations sanctions.
The system is intended to intercept and destroy short and medium-range ballistic missiles during their final phase of flight.