The military expects to put 30,000 National Guard troops on duty in the Gulf states as demands grow for more security and relief assistance after Hurricane Katrina (search), the commander in charge of military relief and rescue efforts said Thursday.

About 24,000 of those will be on the ground in Louisiana and Mississippi in the next three days, Army Lt. Gen. Russel Honore said in a telephone interview with reporters at the Pentagon. He also ordered the amphibious assault ship USS Bataan (search) from the Louisiana coast to waters off Biloxi, Miss., to assist with hurricanend the dock landing ship USS Whidbey Island will join five other Norfolk-based Navy ships that were already under way or in the Gulf as part of the Defense Department contingent being deployed to the stricken region.

In addition, a fast combat support ship based at Naval Station Earl in New Jersey was expected to arrive in the Gulf later Thursday, and there were plans to bring in a rescue and salvage ship to assist with underwater surveys. And the Air Force was sending in a U-2 surveillance and reconnaissance aircraft to get detailed, high resolution photographs of the Gulf Coast area.

Marine Corps spokeswoman Capt. Gabrielle Chapin said the Marine Corps Air Station at New River, N.C., had dispatched six CH-53 and two CH-46 transport helicopters to the Gulf Coast, although she did not have more details. At least 120 Marines were headed to the area from New River, Chapin said.

Also, Lt. Col. Bob Thompson, spokesman for Air Force Reserve Command, said volunteer pilots and crews were flying C-130 transports and HH-60 helicopters from Reserve bases in Florida, Alabama and Texas to ferry medical supplies and bring in para-rescue airmen for search and rescue missions in the stricken region.

The military's plans to assist with recovery efforts don't involve a large-scale shifting of U.S. troops from Afghanistan or Iraq, a spokesman for the U.S. Central Command said Thursday.

But the Pentagon is looking at ways to bring home from the war zones individual service members whose families suffered from the hurricane and need their help, said Lt. Col. Trey Cate, based in Qatar.

Honore said the Mississippi coastline and most structures within three miles of the Gulf of Mississippi were destroyed, and most structures beyond that to Interstate 20 are severely damaged. The challenge, he said, is that the destruction is spread over a large, remote area.

In New Orleans (search), he said, the devastation is concentrated in a smaller area, but the flooding is hampering efforts to access much of the city.