Korean First Vice Foreign Minister Lim Sung-nam made the announcement at the Warsaw summit on a NATO-led mission about Afghan security forces, the Foreign Ministry said.
The ministry said Korea will contribute $45 million to Afghanistan per year from 2018 to 2020. The annual assistance accounts for 0.9 percent of its total annual needs.
The participants of the summit agreed to strengthen Afghan security forces to ensure Afghanistan will not become a hotbed of terrorism.
Last year NATO launched a new non-combat Resolute Support Mission to train, advise and assist Afghan security forces and institutions as the Afghans assumed full responsibility for security following the end of the operation of the International Security Assistance Force in 2014.
In May, NATO foreign ministers agreed to sustain the Resolute Support Mission presence beyond 2016.