The military is finalizing a plan to build three more 7,600-ton Aegis ships from 2022, bringing the total number of these destroyers to six.
The move comes amid an intensifying arms race in the region and deepening squabbles over maritime territory.
A military source said on Sunday the Joint Chiefs of Staff will make a decision on the plan at a meeting late this month.
The ships will cost a total of W3 trillion (US$1=W1,058).
"We need a mobile fleet at Jeju naval base in preparation for the maritime expansion of neighboring nations," a military spokesman said.