South Korea and the US are scheduled to begin a joint navy exercise against North Korean submarines by late June.
A South Korean military official said the joint naval exercise was expected to begin in the final week of June, according to koreaherald.com.
The South Korean Navy is expected to deploy its 1,800t Son Wonil Class submarines and 4,500t KDX II destroyers.
Alongside the South Korean Navy, the US Navy will deploy a fleet of US warships, including an aircraft carrier of the US 7th Fleet for the maritime drills.
South Korea and the US have reinforced their naval cooperation after a North Korean torpedo attack on a Seoul warship.