Iran closes Strait of Hormuz again, citing Lebanon ceasefire violations

(Bloomberg) — Iran said Saturday that it has once again closed the Strait of Hormuz to shipping traffic, citing what it described as violations of a ceasefire agreement in southern Lebanon, raising fresh uncertainty for global oil markets just days after an interim U.S.-Iran agreement paved the way for renewed exports through the critical waterway.

The announcement comes as preparations continue for negotiations in Switzerland aimed at reaching a broader agreement between Washington and Tehran. Iranian state media reported that a delegation led by Parliament Speaker Mohammad Bagher Ghalibaf and Foreign Minister Abbas Araghchi is traveling to the talks, while U.S. officials said technical discussions are already underway.

The immediate impact of Iran's declaration remained unclear. Commercial vessel traffic has continued to move through the Strait of Hormuz in recent days, and U.S. Central Command reported Saturday that 55 merchant vessels carrying more than 17 million barrels of oil had transited the waterway.

Industry observers cautioned that it remains uncertain whether Iran's announcement represents a formal operational closure or an attempt to increase leverage ahead of negotiations.

“Iran announced the closure of the Strait, but it is not clear yet if that is more than rhetoric,” Daniel Shapiro, former U.S. ambassador to Israel and a senior fellow at the Atlantic Council, told Bloomberg. “Meanwhile, they are sending negotiators to Switzerland. That suggests they do not want to lose the benefits they are promised in this MOU.”

The Strait of Hormuz carries roughly one-fifth of global oil and LNG trade and has remained at the center of energy markets since conflict erupted in late February. An interim agreement signed earlier this week raised hopes that exports would gradually return to normal after nearly four months of disruption.

However, uncertainty over shipping rules and future transit requirements continues to cloud the recovery. Earlier this week, Iran indicated that vessels transiting Hormuz would require government authorization and suggested new insurance requirements could eventually be imposed.

Shipping activity has resumed along routes near both the Iranian and Omani coastlines, though portions of the central waterway are still believed to contain mines deployed during the conflict.

Some shipping and security experts expect further disruptions and conflicting signals as negotiations proceed.

“I expect this to happen again and again over the next couple of days and weeks,” Martin Kelly, head of advisory at EOS Risk Group, told Bloomberg. “Iran is using its leverage over the Strait of Hormuz.”

Brent crude settled near $80/bbl on Friday after falling sharply earlier in the week following news of the interim agreement. Analysts have warned that any renewed disruption to Hormuz traffic could quickly reverse those declines when markets reopen.

While oil exports have begun recovering and Gulf producers have started preparing to restore production, market participants continue to monitor whether vessel traffic can return to normal levels and whether upcoming negotiations can produce a more durable agreement between Washington and Tehran.