South Korea on Friday formally appointed Kim Jang-soo, a former national security adviser, as its new ambassador to China amid a growing need to cooperate in the fields of peace and security in the region.

The 67-year-old Kim, also a former defense minister, will replace predecessor Kwon Young-se, according to Seoul's foreign ministry.

It marks the first time that an official with a military background has served as Seoul's ambassador to China after Seoul and Beijing established diplomatic ties in 1992.

Kim served as the national security adviser from March 2013 to May 2014 after working on security and diplomacy affairs on the transition team for President Park Geun-hye, who took office in February 2013.

He served as the defense chief from November 2006 to February 2008 under the administration of the late liberal President Roh Moo-hyun.

The appointment came as South Korea is struggling to walk a diplomatic tightrope between the U.S., Seoul's key ally, and China, Seoul's largest trading partner, over Washington's possible deployment of an advanced missile defense system.

But on the economic front, Seoul and Beijing have intensified their cooperation, including a recent signing of a free trade agreement.

Seoul announced Thursday it will join the China-led Asian Infrastructure Investment Bank as a founding member.

The U.S. hopes to deploy a Terminal High-Altitude Area Defense battery in South Korea to counter ballistic missile threats from North Korea. The move has drawn strong opposition from Beijing, which suspects it is part of a U.S. plan to contain a rising China. (Yonhap)