President Trump said his envoys Steve Witkoff and Jared Kushner will travel to Islamabad on Sunday for another round of negotiations with Iran before the ceasefire is scheduled to end on Tuesday.Why it matters: The talks will be an eleventh hour attempt to reach a deal, at least to extend the ceasefire if not to end the war.Driving the news: Iran attacked several commercial vessels on Saturday after announcing it was once again closing the Strait of Hormuz.That came after Trump had expressed confidence that a peace deal was imminent.The Iranian move came after Trump declined to lift the blockade on the strait of Hormuz, and after Tehran claimed the U.S. introduced new "maximalist" positions.Trump convened an unusual Saturday Situation Room meeting in response to the new crisis. A U.S. official said that at the end of the meeting Trump still expressed a desire to try reach a deal with Iran, before exploring other options. What he is saying: "Iran decided to fire bullets yesterday in the Strait of Hormuz — A Total Violation of our Ceasefire Agreement!" Trump wrote on Truth Social on Sunday morning. Trump noted his representatives would arrive in Islamabad on Monday evening for negotiations."We’re offering a very fair and reasonable DEAL, and I hope they take it because, if they don’t, the United States is going to knock out every single Power Plant, and every single Bridge, in Iran. NO MORE MR. NICE GUY!" Trump wrote."They’ll come down fast, they’ll come down easy and, if they don’t take the DEAL, it will be my Honor to do what has to be done, which should have been done to Iran, by other Presidents, for the last 47 years. IT’S TIME FOR THE IRAN KILLING MACHINE TO END!" he added.The bottom line: After days of assuring the U.S. and the world that the war was over, Trump could soon revert back to his threats to escalate it if the Islamabad talks fail.