Iran's military announced Saturday it has reimposed restrictions on the Strait of Hormuz, citing the US continuation of its blockade on Iranian ports — reversing an earlier opening after Trump refused to lift sanctions as part of negotiations. Global energy markets are tightening as a result; about one-third of all seaborne oil trades through this chokepoint, so shipping disruptions drive up prices worldwide and threaten global supply chains already strained by the ongoing US-Israel conflict with Iran. The situation reflects a breakdown in informal negotiations — Iran opened the strait days ago expecting the US to reciprocate by easing the blockade, but Trump doubled down instead, and both sides are now using the strait as leverage in high-stakes talks over nuclear concessions.