The USS Wasp was the first Navy ship to arrive in the US Virgin Islands and is providing medium and heavy lift helicopters to transport people and supplies, the service said in a statement.
Irma -- a Category 5 storm churning in the Atlantic with 175 mph sustained winds -- killed at least six
people on Wednesday as it devastated small northeastern Caribbean islands such as Barbuda and left hundreds of thousands of customers in Puerto Rico without power.
The Turks and Caicos Islands and the Bahamas are bracing for the massive hurricane
and Florida's governor is warning everyone in his state to be ready to take shelter.
Even with active military service members continuing to support missions in Texas following the widespread flooding caused by Tropical Storm Harvey, the Pentagon is mobilizing a variety of resources to assist FEMA in its Irma response effort.
In one of the largest potential amphibious relief operations ever, four additional US Navy amphibious warships, in addition to the USS Wasp, are in either en route to the region or on standby at various locations off Florida, the mid-Atlantic and the Caribbean to move in for relief operations after Hurricane Irma passes, according to several Navy and Marine Corps officials.
The USS Kearsarge amphibious warship -- with 690 Marines on board -- and the dock landing ship USS Oak Hill are moving toward the area from their position off the coast of Florida.
Both ships had been on their way to Texas for relief operations for Hurricane Harvey.
The USS New York and USS Iwo Jima were loading up disaster relief supplies in Norfolk, Virginia on Thursday, Navy and Marine Corps officials told CNN. The Iwo Jima will carry 260 Marines.
"These ships are capable of providing medical support, maritime civil affairs, maritime security, expeditionary logistic support, medium and heavy lift air support, and bring a diverse capability including assessment, security, route clearance and water purification," according to US Northern Command.
The USS Wasp, USS Kersage and USS Oak Hill will also carry a variety of aerial assets including:
Three UH-1Y Marine Utility Helicopters
Three CH-53E Marine Heavy Lift Helicopters
Five MV-22 Marine Tiltrotor aircraft
Nine MH-60S Navy Medium Lift Helicopters
Airmen with the 621st Contingency Response Wing were also deployed to St. Thomas on a C-17 Globemaster III in support of relief efforts.
The Air Force is also moving personnel and hundreds of aircraft out of the storm's path while continuing to actively support relief operations, according to the service.
50 F-16 Fighting Falcons from the 20th Fighter Wing at Shaw Air Force Base, South Carolina, and more than 100 personnel will evacuate to Barksdale Air Force Base, Louisiana.
11 KC-135 Stratotankers from the 6th Air Mobility Wing and 927th Air Refueling Wing will evacuate from MacDill Air Force Base in Tampa, Florida.
13 F-15 Eagles will evacuate from Jacksonville International Airport, Florida.
21 A-10 Thunderbolt II and two A-29 Super Tucanos will be evacuated from the 23rd Wing at Moody Air Force Base, Georgia.
Non-essential personnel have departed US Southern Command headquarters in Doral, Florida to prepare for the storm, according to a statement to CNN.
"SOUTHCOM will maintain a watch team at the headquarters throughout the weekend to monitor Hurricane Irma and coordinate should it receive a request to support the region," the statement said.
Warships and submarines from Florida to Georgia have also been put out to sea to ride out the storm.