Vice President JD Vance is scheduled to lead a team of United States negotiators in Islamabad on Tuesday for talks with Iran aimed at ending their war, even though Tehran is yet to confirm its participation in this latest round of negotiations.Meanwhile, a fragile two-week ceasefire is poised to expire on Wednesday with no clarity on whether it will be extended amid a spike in tensions over the past two days.The first round of US-Iran talks in Islamabad on April 11 ended without a breakthrough. Since then, the US has imposed a naval blockade on all Iran-linked ships trying to pass through the Strait of Hormuz. Iran has fired at ships trying to transit through the vital shipping route. And early on Monday, the US shot at and then seized an Iranian vessel trying to pass through the narrow waterway.Tehran called the ship’s seizure “piracy” and has threatened retribution. It has refused to join talks under the shadow of threats. Trump has revived his warning that he would order the US military to blow up all bridges and power plants in Iran …