Iran's foreign ministry said Monday it had no plans to send negotiators to Islamabad for a second round of talks with the United States, casting doubt on the main diplomatic track 48 hours before the two countries' ceasefire is set to expire. Foreign Ministry spokesman Esmaeil Baghaei told reporters in Tehran that Washington had "violated the ceasefire from the beginning of its implementation", citing the U.S. blockade of the Strait of Hormuz and the Navy's weekend seizure of an Iranian-flagged cargo ship.

The statement puts the clearest diplomatic opening since the war began, brokered by Pakistan, on the brink of collapse. A breakdown would clear the way for the bombing campaign President Trump threatened Sunday against Iran's power plants and bridges, keep oil markets under pressure after a 5.3 percent jump Monday, and leave Wednesday's ceasefire expiry without a replacement framework.

The Touska seizure

On Sunday, the guided-missile destroyer USS Spruance fired into the engine room of the Iranian-flagged Touska, a cargo vessel nearly 900 feet long, in the Gulf of Oman. Trump said on Truth Social that the Navy "stopped them right in their tracks by blowing a hole in the engine room" after the ship ignored warnings issued over a six-hour period, according to U.S. Central Command. Marines then descended from a helicopter by rope to board the vessel, according to video released by CENTCOM, and took custody. CENTCOM did not answer questions about casualties.

Iran's Revolutionary Guard said it would act against the U.S. military over the seizure, without specifying how. Iran's joint military command called the armed boarding an act of piracy and a ceasefire violation, the state broadcaster reported. China, a heavy buyer of Iranian oil, expressed concern over what it called "the forcible interception", according to the Associated Press, and called for a resumption of peace talks.

Islamabad on lockdown

Pakistan pushed ahead with preparations regardless. The Marriott and Serena hotels in Islamabad cleared guests by Sunday afternoon, the Red Zone housing the National Assembly and foreign embassies was sealed, and thousands of police and paramilitary personnel arrived from across the country, Al Jazeera reported. At least four U.S. government aircraft carrying communications equipment and motorcade support landed Sunday at Nur Khan airbase in Rawalpindi, the primary VIP entry to the capital, according to flight-tracking data cited by Al Jazeera.

Mediators are aiming for a multi-day round that ends in a memorandum of understanding to extend the ceasefire by as much as 60 days and buy space for a longer deal, sources close to the talks told Al Jazeera. The first round on April 11 ran 21 hours and ended without agreement.

The White House said Vice President JD Vance, special envoy Steve Witkoff and senior adviser Jared Kushner would lead the U.S. delegation. Trump said Sunday that Vance would not travel to Islamabad because of security concerns, but press secretary Karoline Leavitt later said Vance would join the delegation.

The deadline and the battlefield

The war is in its eighth week. Abbas Masjedi, head of Iran's Legal Medicine Organization, said Monday that at least 3,375 people had been killed, including 383 children, according to Iran's Mizan news agency. The Associated Press put the broader toll at more than 3,000 in Iran, more than 2,290 in Lebanon, 23 in Israel and more than a dozen in Gulf Arab states, with 15 Israeli soldiers killed in Lebanon and 13 U.S. service members across the region.

Oil prices climbed 5.3 percent to $95.62 a barrel on Monday from Friday's $90.38 close, NPR reported. Roughly a fifth of the world's oil trade normally moves through the strait, and hundreds of vessels are waiting for clearance at each end.

Trump coupled his announcement of the new round Sunday with a threat, posted to Truth Social, that "the United States is going to knock out every single Power Plant, and every single Bridge, in Iran. NO MORE MR. NICE GUY!" The separate 10-day ceasefire between Israel and Hezbollah in Lebanon, which took effect Friday, is holding, though Hezbollah said over the weekend it had planted the device that killed an Israeli soldier in southern Lebanon before the truce began.

The counterpoint

Iran's pattern this past week has been to disavow talks publicly while signaling privately. Iranian sources had indicated Sunday that a delegation could arrive in Islamabad on Tuesday, potentially led by parliament speaker Mohammad Bagher Ghalibaf and Foreign Minister Abbas Araghchi, the same officials who led the April 11 round, according to Al Jazeera. Fahd Humayun, a political scientist at Tufts University, said warring parties "come with the understanding that there is occasionally a gap between public posturing and private positions". An NBC News poll released this week showed Trump's approval rating at a new low, with 63 percent of respondents disapproving of his job performance and two-thirds disapproving of his handling of the Iran conflict and inflation, NPR reported — a political pressure point that could constrain how far the White House pushes if talks collapse. Fox News on Monday led its news brief with the Navy's disabling of the Iranian ship and Iran's Hormuz restrictions.

The ceasefire expires Wednesday. Trump told ABC News that a deal "will happen. One way or another. The nice way or the hard way". Iran's ambassador to Pakistan, Reza Amiri Moghadam, posted on social media: "As long as the naval blockade remains, faultlines remain".