SAN JUAN, Puerto Rico (AP) — Hurricane Dorian posed an increasing menace to Florida Thursday as it pushed over open waters after doing limited damage in Puerto Rico and the Virgin Islands.

The U.S. National Hurricane Center said Dorian was expected to grow into a potentially devastating Category 3 hurricane before hitting the U.S. mainland late Sunday or early Monday somewhere between the Florida Keys and southern Georgia.

“Hurricane Dorian looks like it will be hitting Florida late Sunday night,” President Donald Trump tweeted. “Be prepared and please follow State and Federal instructions, it will be a very big Hurricane, perhaps one of the biggest!”

Dorian blew through the Virgin Islands as a Category 1 hurricane on Wednesday while raking nearby Puerto Rico with high winds and rains.