This was reported by the American Hurricane Tracking Center on its Twitter page.
"Dorian" became a hurricane near the island of St. Thomas as part of the US Virgin Islands, "the statement said.
Hurricane #Dorian Advisory 17A: Dorian Becomes a Hurricane Near St. Thomas in the US Virgin Islands. https://t.co/VqHn0u1vgc- National Hurricane Center (@NHC_Atlantic) August 28, 2019
Earlier, US President Donald Trump said that the federal authorities are closely monitoring the tropical storm Dorian, which is approaching Puerto Rico, and if necessary, are ready to help the island.