The US State Department approved the potential sale of F-35 fighter jets and related equipment to South Korea at an estimated cost of $5.06 billion, according to a statement Wednesday.
Congress has been notified of the sale of up to 25 jets, according to the Defense Security Cooperation Agency.
"The proposed sale will improve the Republic of Korea’s capability to meet current and future threats by providing credible defense capability to deter aggression in the region and ensure interoperability with U.S. forces," it said.
It noted the sale will augment Seoul's operational aircraft inventory and enhance its air-to-air and air-to-ground self-defense capability.
"Korea already has F-35s in its inventory and will have no difficulty absorbing these articles and services into its armed forces," it added.
The sale came amid North Korea's repeated ballistic missile launches in violation of UN sanctions Kim Jong-un's visit to Russia.