South Korea's defense chief has suggested that North Korea could launch another spy satellite as early as the end of March.

North Korea announced last November that it put its first military reconnaissance satellite into orbit. The country's leader Kim Jong Un revealed in December a plan to launch three more satellites in 2024.

South Korean Defense Minister Shin Won-sik told local media the first of those three planned launches could come at the end of next month.

Shin declined to disclose the basis for his remark, but revealed that the South's military plans to launch a spy satellite from the US in early April.

He pointed out that if Kim orders a launch earlier than South Korea's, the North's military is capable of doing so in March.

Shin also commented on the military reconnaissance satellite that Pyeongyang claims to have successfully launched, noting that "it shows no signs of functioning and is merely orbiting without activity."