"You can not afford to stay on an island with a category five hurricane coming at you", said Martin Senterfitt, the emergency operations centre director in Monroe County in Florida. "This is 185 miles per hour winds and they're tracking it even higher than that at some times".
The massive Category 5 storm packed winds of up to 185 miles per hour, the US National Hurricane Center said.
Tropical Storm Katia formed early Wednesday off the coast of Mexico.
Whether by plane, auto or train, hundreds of thousands of people are scrambling to get out of South Florida ahead of Hurricane Irma, a massive system that forecasters say is the most powerful storm to hit the Atlantic Coast in more than a decade.
The National Hurricane Center says that the chance of direct impacts to Florida continues to increase, but "it is too soon to specify the timing and magnitude of these impacts".
"On Necker Island we have constructed really strong buildings (with hurricane blinds) that should be able to handle extreme weather pretty well, though with a Category 5 hurricane nearly nothing can withstand it", he wrote on his blog.
Hurricane Irma has strengthened into a Category 4 storm as it approaches the northeast Caribbean
Schools, public services and ports have been closed.
The President said he and Congress "have many, many things that are on the plate".
Hollingsworth said Irma is expected to start impacting the Florida Keys on Friday, with the eye arriving as early as Saturday morning before the system moves north. As of Wednesday morning, no evacuation orders have been issued.
Residents throughout the state have spent the past two days stocking up on water, gasoline and other supplies.
As Florida prepares for Hurricane Irma and Jose swirls in the ocean, Tropical Storm Katia popped up in the Gulf of Mexico to become the 11th named storm of the 2017 Atlantic hurricane season.
The Dominican Republic has issued a Hurricane Warning for its northern coast, according to the National Hurricane Center's 5 p.m. advisory.
May set to agree on €55 billion Brexit bill, Sunday Times says
Jeremy Corbyn is set to demand his MPs vote against the Brexit bill when it finally comes before the Commons this week. The Prime Minister is facing a major battle to get the EU Withdrawal Bill through parliament.