Iran Reimposes Controls on Strait of Hormuz

Iran’s military reimposed controls over the Strait of Hormuz on April 18, 2026, requiring commercial vessels to obtain Iranian approval to transit the waterway between Iran and Oman.

On April 17 Iran’s foreign minister announced the strait was open for the duration of a ceasefire tied to a Lebanon-related truce. President Trump posted that the waterway was ‘fully open and ready for business’ and would ‘never’ close.

Less than 24 hours later Iranian authorities reinstated coordination rules for passage. Regional shipping reports indicated multiple vessels were turned away or rerouted after the controls returned.

Deputy Foreign Minister Saeed Khatibzadeh rejected the account that the strait would remain open, stating vessels must coordinate with Iranian forces before passage. Parliament Speaker Mohammad Bagher Ghalibaf accused the U.S. president of making ‘7 claims, all 7 false.’

Iranian officials placed responsibility for the renewed restrictions on the U.S. naval blockade of Iranian ports and recent strikes, and said Tehran had not agreed to keep the strait permanently open.

The ceasefire tied to the brief reopening remains fragile, with some reports indicating its terms could lapse around April 22. The U.S. naval blockade of Gulf ports continues.

The Strait of Hormuz is a narrow channel through which roughly 20% of global crude oil and liquefied natural gas normally flows. Markets reacted quickly: on April 17 Brent crude fell about 9% to near $92 a barrel and West Texas Intermediate dropped into the low $80s after the reopening announcement. By April 18 Brent futures moved toward $94–$96 per barrel and WTI rose toward $90 as traders reassessed supply risk.

Shipping companies signaled continued caution while security guarantees remain unresolved.

Cryptocurrency markets also swung. Bitcoin briefly traded above $78,000 on April 17 before pulling back to roughly $75,800–$77,100 on April 18; it was trading just above $76,000 early Saturday Eastern time. Crypto-related equities that rose with the initial reopening gave back gains after the reversal.

With vessels now required to coordinate with Iranian forces, transit rules and market responses will continue to evolve until the U.S. blockade ends or Tehran alters its conditions.