The Trump administration on Monday narrowed its waiver of the Jones Act while extending it for another 90 days, leaving in place fewer U.S. shipping restrictions in an effort to keep fuel flowing amid the Iran war. Trump issued his first 60-day waiver of the Jones Act on March 17, less than three weeks after the U.S. and Israel started the war by launching heavy strikes on Iran. The Trump administration extended the waiver in mid-May for another 90 days. The latest extension, however, will be narrowed to apply only to vessels hauling certain energy resources, a White House official told CNBC. The extension will also require the Pentagon to consult with the U.S. Maritime Administration and determine if the waiver applies to each individual shipping voyage, the official said.