Updated

The memorandum of understanding between Washington and Tehran expired on Monday, August 17, and US President Donald Trump rejected an extension, saying Iran should "put up the white flag of surrender" while US officials asserted control over the Strait of Hormuz. The lapse of the accord has left the waterway at the center of the standoff, with commercial traffic disrupted and both sides trading blame over who is responsible for the closure. On Tuesday, August 18, Iran's top negotiator, parliament speaker Mohammad Bagher Ghalibaf, said the Strait of Hormuz "will not be opened until the American commitments stipulated in the memorandum of understanding... are implemented," specifically citing the lifting of the US naval blockade. The statement makes explicit that Tehran is treating the closure as leverage tied to US compliance with the expired MoU, hardening a position that keeps one of the world's most important energy chokepoints shut and sets up a direct clash with Washington's insistence that it controls the strait.