The United States has reimposed a naval blockade on Iranian ports as military operations against targets in Iran entered a fourth consecutive day. In a statement cited by CNN, the US military said the blockade had been restored after an earlier enforcement period between April and June. The development came amid renewed American strikes on Iranian targets. Iranian state media reported explosions in the southern port city of Bandar Abbas and areas near Sirik, although the full extent of the damage was not immediately clear. Iran has also continued retaliatory operations against countries allied with Washington in the region, including Kuwait, further weakening prospects for an immediate ceasefire. US President Donald Trump warned that American forces could target Iranian bridges and power facilities next week unless Tehran returns to negotiations. Trump has previously issued similar threats as part of his pressure campaign to force Iran back to the negotiating table. In a separate announcement, the president reversed an earlier decision to impose a 20 percent reimbursement charge on cargo passing through the Strait of Hormuz. Trump said the proposed fee would instead be replaced by investments from Gulf countries in the United States. Neither Washington nor Tehran has announced any immediate breakthrough toward ending the hostilities.