The United States has begun moving elements of an anti-missile defence system into South Korea in response to heightened concerns over developing nuclear weapons capabilities in North Korea.

The movement of the Terminal High Altitude Area (THAAD) defence system parts sparked criticism from several actors in the region including China and the leading presidential contender in South Korea. The systems, which are being set up on a golf course roughly 250 km south of Seoul, are expected to be operational by the end of the year, according to the South Korean defence ministry.

“South Korea and the United States have been working to secure an early operational capability of the THAAD system in response to North Korea's advancing nuclear and missile threat,” South Korea’s defence ministry said in a statement.

But China has expressed concern over the increased US military presence in the country, saying that installing the THAAD anti-missile system’s advanced radar could undermine its security and do little to deter Kim Jong-un's North Korea from conducting further tests. The United States and South Korea say that the defences are only aimed against North Korea.

“China strongly urges the United States and South Korea to stop actions that worsen regional tensions and harm China's strategic security interests and cancel the deployment of the THAAD system and withdraw the equipment,” Geng Shuang, a Chinese foreign ministry spokesman said.

Installing those defences comes as concerns over North Korea’s nuclear arsenal and missile testing have mounted. The United States and South Korea have been conducting military exercises in the region in response to concerns that North Korea might test their nuclear weapons capabilities for a sixth time.

In pictures: North Korea military drill Show all 8 1 /8 In pictures: North Korea military drill In pictures: North Korea military drill North Korea's leader Kim Jong Un watches a military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) is seen in this handout photo by North Korea's Korean Central News Agency (KCNA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) is seen in this handout photo by North Korea's Korean Central News Agency (KCNA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill A military drill marking the 85th anniversary of the establishment of the Korean People's Army (KPA) KCNA/Handout via REUTERS In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video In pictures: North Korea military drill This image made from video of still images broadcast in a news bulletin by North Korea's KRT, shows what was said to be a 'Combined Fire Demonstration' held to celebrate the 85th anniversary of the North Korean army, in Wonsan, North Korea. KRT via AP Video