The Defense Security Cooperation Agency (DSCA) said on Tuesday that the U.S. State Department has approved the purchase which is estimated to cost US$6.2 billion.
The procurement is being made under the Foreign Military Sales (FMS) program, which is part of the U.S. strategy to supply weapons to foreign governments and requires congressional endorsement.
"This proposed sale will improve [South Korea's] capability to meet current and future threats by increasing its critical air defense capability to deter aggression in the region and to ensure interoperability with U.S. forces," the DSCA said.
U.S. aircraft maker Boeing and aerospace and defense company Raytheon Technologies are expected to handle the delivery as the primary contractors.