BEIJING (Reuters) - China’s Foreign Ministry expressed serious concern on Saturday after South Korea said it will proceed with the deployment of four additional units of the U.S. THAAD anti-missile defence system.

The deployment will not resolve South Korea’s security concerns and will only make things more complex, the ministry said, reiterating a Chinese call for the system to be withdrawn.

North Korea said earlier on Saturday it had conducted another successful test of an intercontinental ballistic missile (ICBM) that proved its ability to strike all of America’s mainland.