The radar of an advanced US missile defense system in South Korea detected the launch of a North Korean ballistic missile two days ago, South Korea's defense minister told lawmakers on Tuesday.

The Terminal High Altitude Area Defense system, which became operational earlier this month in South Korea, aims to destroy short- and medium-range ballistic missiles amid growing nuclear and missile threats from North Korea.

North Korea test-launched what appears to be a long-range ballistic missile on Sunday, claiming that it can carry a "large nuclear warhead."

Defense Minister Han Min-koo said at a meeting of the National Assembly's defense committee that the THAAD's radar in South Korea detected North Korea's launch on Sunday, citing confirmation from the US.

Han said South Korea's military separately detected the Sunday launch, using its own intelligence assets.

The remarks by Han suggested that the South Korean and US militaries closely shared data on the operation of the THAAD in South Korea.

Seoul and Washington say the THAAD is defensive in nature and not a threat to Beijing and Moscow. (Yonhap)