The forces, however, will not join a US-led coalition, but conduct independent operations, the Ministry said, a move seen as reflecting Seoul's consideration of relations with Tehran and Washington's request for contribution to its campaign to secure the waters off Iran, Yonhap News Agency said in a report.
"In consideration of the current situation in the Middle East, the government has decided to temporarily expand the Cheonghae Unit's sphere of activity in order to guarantee safety of our people and the freedom of navigation of our vessels," the Ministry said in a statement.
The 300-strong Cheonghae Unit, which has been on an anti-piracy mission in the Gulf of Aden off Somalia since 2009, will broaden its mission areas into the Gulf of Oman, and further to the Persian Gulf, starting Tuesday, as the 31st batch of the rotational troops along with the 4,400-tonne destroyer, the Wang Geon, is to assume the role on the day, according to the Ministry.
"Since May last year, when tensions began to heighten in the Middle East, we've been reviewing diverse options," Yonhap News Agency quoted a senior Defense Ministry official as saying, adding that the government prioritizes the safety of South Korean people and vessels.
Before announcing the decision, the Ministry had consultations with the US and also explained reasons for the decision to Iran through diplomatic channels, according to the official.
As for the meaning of the "temporary" expansion of its role, the Ministry official said it will be valid "until situations in the Middle East improve".
As the world's most important oil passageway and a choke point between the Arabian Gulf and the Gulf of Oman, the strait is the route to the open ocean for more than one-sixth of global oil production and 70 per cent of South Korea's oil imports.
Tensions in the region have further mounted after Iran launched missile attacks on US troops in Iraq on January 8 in retaliation for an American drone attack that killed Iranian Major General Qasem Soleimani in Baghdad on January 3.
( With inputs from IANS )