ROME (AP) — The head of Iran's nuclear agency warned the United States on Tuesday against undermining the 2015 nuclear deal, saying international nonproliferation efforts as well as Washington's international standing would suffer as a result. Iranian nuclear chief Ali Akbar Salehi told an international conference on enhancing nuclear safety that Washington's recent "delusionary negative postures do not augur well" for keeping the deal intact. He said Iran didn't want to see the deal unravel but that "much more is at stake for the entire international community than the national interests of Iran." U.S.