Iranian state TV said Tehran will welcome a Pakistani delegation led by army chief Asim Munir on Wednesday, after the Islamic republic confirmed that exchanges with the US had continued via Pakistan after failed talks in Islamabad to end the war.
State TV reported that Iranian Foreign Minister Abbas Araghchi will welcome the delegation, which will bring a new message from Washington following the negotiations in the Pakistani capital over the weekend.
Iran's military threatened on Wednesday to shut down Red Sea trade unless the United States lifted its naval blockade on Tehran's ports, saying the ceasefire was at risk.
The warning came after President Donald Trump indicated peace negotiations could resume this week, and as Iran confirmed the sides had kept talking via Pakistan after a first round of negotiations fell flat.
US Vice President JD Vance, who led the weekend talks, said the Islamic republic was being offered a "grand bargain" to end the six-week war and address the decades-old dispute over Tehran's nuclear programme.
But for now, both sides seemed intent on keeping up the pressure.
Washington has sought to turn the screws on Tehran with a blockade of its ports, with US Central Command saying overnight that American forces "have completely halted economic trade going into and out of Iran by sea".
The picture based on recent maritime tracking data in the Strait of Hormuz was less clear-cut, and Iran's Tasnim news agency reported Wednesday that shipping had continued from southern Iran.
But the head of Iran's military central command centre warned a US failure to lift the blockade would constitute "a prelude" to violating the two-week ceasefire.
Unless Washington relents, Iran's armed forces "will not allow any exports or imports to continue in the Persian Gulf, the Sea of Oman and the Red Sea," said Ali Abdollahi.