WASHINGTON—Iran and the U.S. have agreed on an interim peace deal, the two nations announced Sunday, a potentially major breakthrough after nearly four months of fighting that created global political and economic turmoil. A deal is set to be signed Friday, President Trump and Pakistani negotiators said. Trump had earlier indicated he hoped a deal would be signed Sunday. Neither side provided a specific list of agreed-upon details in the deal. Trump said the Strait of Hormuz would be reopened on Friday, indicating in a social-media post the time was needed “for purposes of mine removal.” In an earlier post, Trump said…