>> glor: okay, paula reid, thank you. iran fired a verbal salvo at the united states over the weekend. and president trump fired right back. it began when iran's president warned that the war with his country, a war, would be the mother of all wars. more now from weijia jiang, also at the white house. >> reporter: mr. president, any concerns about provoking tensions with iran? >> not at all. >> reporter: president trump this afternoon downplayed the escalation intention between washington and tehran. the comments came after his tweet late yesterday addressing president rouhani. reever ever threaten the united states again," he wrote, "or you will suffer consequences the likes of which few throughout history have ever suffered before." the president was responding to remarks from rouhani earlier that day. "america should know that peace with iran is the mother of all peace, and war with iran is the mother of all wars." rouhani's government has been under pressure as iran's economy