Representatives of citizen groups protested outside the Ministry of National Defense in Seoul on Friday morning, as US Defense Secretary James Mattis met with his South Korean counterpart Han Min-koo. /Tangxin Photo

The demonstrators protested against the US Terminal High Altitude Area Defense (THAAD), demanding that the US and South Korea withdraw the decision to deploy the missile system immediately. /Tangxin Photo

However, according to South Korea's defense ministry, the US and South Korea have agreed to deploy the THAAD system in South Korea this year to counter the threat from North Korea. /Tangxin Photo

China and Russia have strongly opposed the deployment as the THAAD's X-band radar which can peer deep into the territories of the two countries and possibly changing the strategic balance between the powers. the concern is it could increase the chances of an arms race in the region. /CFP Photo