New Delhi, April 19 -- Iran said it fully reopened the Strait of Hormuz to commercial vessels, but questions lingered Saturday about how much freedom ships actually had to transit the waterway as Tehran maintained its grip on the who got through and threatened to close it again if the U.S. kept in place its blockade of Iranian ships and ports.

Iran's Friday announcement about the opening of the crucial body of water, through which 20% of the world's oil is shipped, came as a 10-day truce between Israel and the Iranian-backed Hezbollah militant group in Lebanon appeared to hold.

U.S. President Donald Trump, meanwhile, said the American blockade "will remain in full force" until Tehran reaches a deal with the U.S., including on its nuclea...