Published: Apr 29, 2010 5:57 PM EDT

WASHINGTON (AP) - The Obama administration is promising an all-out response to the massive oil spill that is now expected to reach the Gulf Coast within a day.

The White House is sending top officials to the region to help coordinate defenses against the potential environmental disaster.

Coast Guard Rear Adm. Sally Brice O'Hare told reporters at the White House that the agency is "being very aggressive" and is "prepared for the worst case."

Federal officials also said inspections of all oil rigs in the Gulf will begin immediately, and subpoena powers will be used in the investigation. But they say the priority is to support the oil company BP PLC in using booms, skimmers, chemical dispersants and even fire to fight the oil surging from the seabed.

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