During his tour aboard her, "Iowa" transported President Franklin D. Roosevelt to and from the Teheran Conference in Tehran, Iran in November–December 1943, then steamed to the Pacific, where she supported U.S. Navy air strikes against Kwajalein and Eniwetok in the Marshall Islands during the Marshall Islands campaign in January–February 1943, against Truk in the Caroline Islands during Operation Hailstone on 17–18 February 1944, and against Tinian in the Mariana Islands.