South Korea’s military is operating a surveillance and detection system in preparation of a possible missile launch by North Korea.

A senior Navy official said two seven-thousand-600-ton Aegis destroyers with SPY-1 radar, which can track targets as far as one-thousand kilometers away, have been on standby on the east and west coasts of the Korean Peninsula. The source said if the North fires off a missile, South Korea will trace its trajectory.

The South Korean military is also operating the Green Pine missile defense radar system on land and the early warning aircraft “Peace Eye” to enhance detection.

South Korean and U.S. military authorities have increased reconnaissance efforts in light of the possibility that North Korea may test fire its Musudan missile from an east-coast missile base. The Musudan has a range of three to four-thousand kilometers.