The head of the minor opposition Justice Party says the government will have to seek parliamentary approval before expanding operational areas of South Korea's anti-piracy unit.

During a New Year's press conference on Tuesday, Sim Sang-jung said fighting piracy was the objective behind the extension of the Cheonghae Unit's operation in the Gulf of Aden region last year, adding changing the unit's objective requires approval from the National Assembly.

Sim said her party opposes any form of troop deployment that may show hostility towards Iran and that it cannot support deploying the Cheonghae Unit to the Strait of Hormuz.

The remarks come after Seoul decided to conduct independent operations to help protect South Korean vessels passing through the strait instead of joining the U.S.-led coalition in the strategic waterway.

The decision apparently reflects Seoul's consideration of its relations with Tehran, while responding to Washington's request for contributions to its campaign to secure the Strait of Hormuz.