The US and South Korea have agreed to deploy the THAAD system in South Korea this year to counter the threat from the DPRK. /CFP Photo

The THAAD system is designed to shoot down incoming missiles at an altitude of 40-150 km, but critics point out that most of DPRK's missiles fly at an altitude of less than 40 km. /CFP Photo

China and Russia have strongly opposed the deployment as the X-band radar of the THAAD can peer deep into the territories of the two countries, whcih could change the strategic balance between the powers and increase the chance of an arms race in the region. /CFP Photo

Earlier on Friday, South Koreans protested outside the Ministry of National Defense in Seoul, demanding immediate withdrawal of the missile system. It seemed that the protests made no difference to the agreement. /CFP Photo