US-Iran technical talks are underway on Sunday, with Qatari mediators involved. Ahead of the talks, likely focused on Iran's nuclear program, Tehran attempted to reassert leverage over the Strait of Hormuz following renewed Israel-Hezbollah fighting in Lebanon.

Iran announced the closure of the strait on Saturday, framing the move as retaliation for alleged violations of the US-Iran interim peace deal. 

Early Sunday, maritime intelligence and risk analytics firm Windward wrote on X, "Hours after the IRGC's closure announcement, AIS traffic through the Strait of Hormuz suggested business as usual."

Hours after the IRGC's closure announcement, AIS traffic through the Strait of Hormuz suggested business as usual.

But overnight, the picture shifted: zero AIS transits were recorded through the strait, and only two non-Iranian commercial vessels were AIS-visible this morning.… pic.twitter.com/F4djrrT38m

— Windward (@WindwardAI) June 21, 2026

"But overnight, the picture shifted: zero AIS transits were recorded through the strait, and only two non-Iranian commercial vessels were AIS-visible this morning. Hesitation is back in an already unpredictable corridor," Windward continued.

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However, Bloomberg data show that after vessel transits through the strait spiked to 23 on Thursday, shortly after the interim peace deal was signed and one day before the Hormuz chokepoint reopened, the transit count is now 9 today.

There are reports that the Islamic Revolutionary Guard Corps warned vessels not to approach the critical waterway, citing Israeli actions in Lebanon and alleged US violations of ceasefire commitments. It remains unclear whether Iran has actually enforced the closure.

President Trump insisted on Saturday that "NO TOLLS" would be charged on ships transiting Hormuz during or after the 60-day interim ceasefire. But he noted, "unless they are imposed by and for the United States of America, should the deal not be completed, for services rendered as the Guardian Angel to the countries of the Middle East for purposes of both past, present, and future reimbursement of costs."

Brent crude closed around $80 a barrel last week after the US and Iran reached an interim deal to lift the US blockade and reopen the Strait of Hormuz, easing fears of a prolonged Gulf supply shock.

This prompted Goldman analyst Daan Struyven to forecast on Wednesday that crude prices would normalize to pre-war levels by the end of July and that regional crude production would recover by October.

Struyven estimates that Hormuz flows would need to rise by about 13 million barrels a day from current levels to reach roughly 70% of pre-war volumes.

The problem with Hormuz is that Tehran is now using the narrow, critical waterway as leverage for technical talks. That suggests Iran could continue to spark uncertainty during today's negotiating window, then signal a reopening if talks make progress before NYMEX WTI futures open later this evening.