South Korea will expand the operational area of the anti-piracy Cheonghae Unit regarding its Hormuz troop dispatch, Yonhap News agency reported on Tuesday.
South Korea's Ministry of Defence also confirmed the news.
The United States had previously urged South Korea to help guard oil tankers in the region.
South Korean President Moon Jae-in said last week that South Korean could possibly send troops to the Hormuz Strait, joining the US-led coalition, but added that the decision was impacted by numerous factors.
The Strait of Hormuz is a crucial channel that oil producers use to transport crude from the Middle East to markets around the world. The region has recently become a potential conflict zone, after a batch of attacks on tankers in its Gulf waters and a drone attack against Saudi-Aramco's oil facilities, with the US putting the blame on Iran.