President Donald Trump said Monday he is still pursuing a diplomatic resolution with Iran despite growing doubts over whether negotiations are actually taking place. Trump added that he hopes Iran changes course because "they cannot have a nuclear weapon." RELATED STORY | Trump says he will order halt to Iran strikes after parameters reached for deal to end warThe comments came one day after Trump called off additional U.S. strikes against Iran, saying negotiations would begin Monday. Trump said the canceled operation would have been the largest U.S. military action in more than half a century. IN CASE YOU MISSED IT | Vance, Caine raised concerns about escalating war in Iran, sources say as US pauses strikes