Hurricane Dorian is expected to strengthen into a dangerous Category 3 storm on Friday as it heads towards the US mainland.
It's expected to hit Florida even harder than previously thought, with winds of at least 178 km/h.
Florida Governor Ron DeSantis expanded a state of emergency to prepare for Hurricane Dorian, which is set to make landfall on the Atlantic coast early Monday as a dangerous Category 4 storm.
US President Donald Trump described the storm as "an absolute monster" in a video posted on Twitter.
He also cancelled a visit to Poland in order to monitor relief measures and announced that Vice President Mike Pence would go in his place.

Iran says no final decision made on deal
Two killed, 10 injured in Ukraine attack on Russia's border Bryansk region
Trump cancels US strikes on Iran, citing progress in talks
South Korea court sentences ex-President Yoon to 30-year jail term in drone case
Thai king's eldest daughter dies, aged 47, after long illness