The results of an environmental impact assessment required for the temporary deployment of additional US missile interceptor launchers will be released next week, a presidential aide said Friday, raising the prospects of their earlier-than-expected installation.

The Ministry of National Defense has been conducting the assessment that President Moon Jae-in views as a legitimate domestic procedure for hosting a Terminal High Altitude Area Defense system aimed at countering North Korea's escalating nuclear and missile threats.

"Currently, a small-scale environmental impact assessment is under way, and its results are expected to come out next Monday ... though it is still not definitive yet," the official told reporters on condition of anonymity.

Soon after Pyongyang launched another long-range missile on July 28, Moon ordered his government to seek the deployment of additional launchers to a southern county in addition to the two already deployed launchers.

A THAAD battery consists of six truck-mounted launchers, 48 interceptors (eight per launcher), a fire control and communications unit and an AN/TPY-2 radar.

Regarding a lawmaker's claim that the US demanded the dispatch of additional launchers by next Wednesday, the official said he was unaware of it and that Seoul is closely coordinating the deployment schedule with Washington. (Yonhap)