By Brittney Melton Good morning. You're reading the Up First newsletter. Subscribe here to get it delivered to your inbox, and listen to the Up First podcast for all the news you need to start your day. President Trump says he's postponed military strikes against Iranian power plants, after he threatened on Saturday to "obliterate" them if Iran didn't reopen the Strait of Hormuz in 48 hours. On social media this morning, Trump said the U.S. had "very good and productive conversations" over the past two days, and that he would postpone strikes on Iranian power plants and energy infrastructure for five days, "subject to the success of the ongoing meetings and discussions." Cargo vessel, Ali 25, in the Gulf, near the Strait of Hormuz on March 22, 2026 in northern Ras al Khaimah, United Arab Emirates. Getty Images hide caption Congress returns to session this week, as Democrats and Republicans struggle to negotiate a deal to fund the Department of Homeland Security to help alleviate chaos at U.S. airports.…