The North's state-run Korean Central News Agency (KCNA) also warned of a "nuclear holocaust" on the peninsula in the case of war.
The South's defense ministry said last week it would buy US-made surface-to-surface missiles capable of hitting most North Korean strategic targets.
The ATACMS Block 1A Missiles have a range of 300 kilometers (186 miles), much greater than existing South Korean missiles.
"What merits serious attention is that the missile deployment is part of the US arms buildup for a war of aggression against the DPRK (North Korea)," KCNA said.
"Once they are tipped with US nuclear warheads, Koreans will suffer a nuclear holocaust and all their territory will turn into debris."
Yonhap news agency said South Korea would purchase 110 missiles for deployment next year near the border with North Korea.
The new missile deployment plan was made possible by a military accord in 2001 under which South Korea was allowed to possess missiles with a range of up to 300 kilometers to better cope with North Korea's missile threat.
North Korea has already deployed Rodong missiles with a range of 1,300 kilometers, while actively developing longer-range Taepodong missiles with a range of up to 6,000 kilometers, according to South Korean analysts.
The United States, under a 50-year-old mutual defense treaty, stations 37,000 troops in South Korea, and has performed key military functions since the end of of the 1950-53 Korean War.