The US military says it has begun deploying a controversial missile defence system in South Korea.
The Terminal High-Altitude Area Defense system (Thaad) is designed to protect against threats from North Korea.
The move to begin installing the system comes a day after the North launched four ballistic missiles, breaking international sanctions.
But its planned deployment has angered many in North and South Korea and around the region.China is furious at what it sees as an encroachment of US military power, while many South Koreans believe the defence system will become a target, endangering people who live around the military sites.
The US Pacific Command said Monday’s launch of multiple missiles confirmed "the prudence of our alliance decision last year to deploy Thaad to South Korea".
"We will resolutely honour our alliance commitments to South Korea and stand ready to defend ourselves, the American homeland, and our allies," Admiral Harry Harris, commander of the South Pacific Command, said in a statement.
What is the Terminal High Altitude Area Defense System (THAAD)?
Shoots down short- and medium-range ballistic missiles in the terminal phase of their flight
Uses hit-to-kill technology - where kinetic energy destroys the incoming warhead
Has a range of 200km and can reach an altitude of 150km
US has previously deployed it in Guam and Hawaii as a measure against potential attacks from North Korea