In a sharp move to counter recent missile launches by North Korea the US sent its Terminal High Altitude Area Defense (THAAD) system to South Korea on Monday evening. The North Koreans had just launched four ballistic missiles into the Sea of Japan the day before.

Watch the arrival of the THAAD missile system to South Korea

Sen. John McCain, a Republican from Arizona and chairman of the Senate Armed Services Committee, hailed the development, calling it “a positive step forward for U.S.-ROK cooperation to confront North Korea’s escalating missile threat.”