WASHINGTON — U.S. President Donald Trump says the U.S. Navy is clearing Iranian mines from the Strait of Hormuz, a vital sea route for oil shipments whose disruption is increasingly threatening the global economy. Sweeping for underwater explosives could take months despite a tenuous ceasefire between the United States and Iran in the weekslong war, experts say. Any future claims that the U.S. cleared the waterway where 20 per cent of the world’s oil typically passes might fail to convince commercial freighters and their insurers that it is finally safe. “You don’t even have to have lain mines — you…