The U.S. Navy's Fifth Fleet said Wednesday any disruption of traffic in Strait of Hormuz—one of the world's most important oil routes—"will not be tolerated." A senior Iranian official threatened on Tuesday to cut off its oil flow through the Strait of Hormuz if the U.S. moved forward with its plans to impose economic sanctions on the country in an attempt to thwart its nuclear ambitions. As President Obama prepared to sign in new sanctions that could substantially reduce Iran's oil revenue, Iran's first vice president, Mohammed-Reza Rahimi, vowed to block all oil exports via the Strait of Hormuz, a move that could stir military conflict among countries dependent on its supply. A White House spokesman said the president, who is currently vacationing in Hawaii, would not be commenting on Rahimi's threat. Meanwhile, oil prices fell on Wednesday for the first time in seven days, on worries over the European debt crisis continued.