Korean ships' ties to US companies keep outlook bleak for Hormuz passage

A tanker sits anchored in Port Sultan Qaboos in Muscat, Oman, March 12, as traffic is down in the Strait of Hormuz. Reuters-Yonhap

The outlook for Korean ships' passage through the Strait of Hormuz remains bleak, as Iran’s envoy to Seoul said Korean vessels may pass only if they are not associated with the United States, while many domestic refiners are closely tied to U.S. companies, security and international trade analysts said Friday.

As one of the world’s most critical energy chokepoints, the strait handles about 70 percent of Korea’s imported crude. According to the shipping industry, a total of 26 Korean‑flagged vessels, most of them oil and petroleum product carriers, are tied up in the Persian Gulf as Iran effectively controls the strait amid a widening conflict with the U.S. and Israel.

The outlook followed Thursday's press conference in Seoul, where Iranian Ambassador Saeed Koozechi identified Korea as “non‑hostile,” in line with Tehran’s earlier announcement that coordinated ships from the country may transit the strait. But the envoy said passage would be conditional, noting that it is “only possible through prior agreement” and that “any activities serving the interests of the U.S. or Israel may be subject to sanctions.”

Iranian Ambassador to Korea Saeed Koozechi speaks during a press conference at the country’s embassy in Seoul’s Yongsan District, Thursday. Yonhap

Regarding the ambassador's remarks, an analyst at a diplomatic and security think tank said on condition of anonymity, “It would be too early to jump to conclusions or be overly optimistic about our vessels freely transiting the waterway.”

Also speaking on condition of anonymity, a researcher at the Korea International Trade Association (KITA) voiced a similar view.

“Korean refiners are walking a fine line considering their relations, directly or indirectly, with U.S. businesses that can be cited as a reason for Iran’s sanctions,” the researcher said.

According to the Korea Petroleum Association, the exports of four domestic refiners — SK Energy, GS Caltex, S-Oil and HD Hyundai Oilbank — totaled $40.71 billion in 2025, with $4.33 billion, or 10.2 percent, going to the U.S.

Among the four, GS Caltex has 50 percent of its stakes owned by the U.S. company Chevron, S-Oil has 63.4 percent of its stakes held by Saudi Arabia’s Aramco, which has investment ties with the U.S., and HD Hyundai Oilbank has 17 percent of its stakes also owned by Aramco.

“Under the circumstances, Korean‑flagged oil tankers could serve as leverage for Tehran to pressure U.S. firms and the White House if the situation turns against Iran,” the KITA researcher added.

Seoul’s Military Manpower Administration, meanwhile, said 40 Korean nationals serving as reserve service members are currently aboard 17 of the 26 ships tied in the Persian Gulf.

The onboard ship reserve service is a form of alternative military service that allows qualified mariners and engineers to serve aboard commercial vessels for three years instead of completing the usual 18-month mandatory military service.

“We are monitoring the situation daily, together with the Ministry of Oceans and Fisheries and relevant parties, and paying close attention to the safety and needs of the crews,” administration chief Hong So-young said.