Obama Aide: No New Drilling Until Oil Rig Blast Explained

With reports that floating oil from a huge spill in the Gulf of Mexico has reached Louisiana shores, a top aide to President Obama said Friday no "additional drilling" for offshore oil will be approved until investigators determine what caused the recent explosion on a deep water rig.

In late March, Obama lifted a decades-old moratorium on oil drilling off the mid- and south-Atlantic coasts, areas in the Gulf not currently leased, and in waters off Alaska. But no new leases have been granted as yet, and White House adviser David Axelrod said "none will until we find out what has happened here." An explosion last week on the BP rig Deepwater Horizon apparently killed 11 workers, whose bodies have not been found, and released oil from a deep well that has formed a dark slick moving toward the shores of states along the Gulf Coast.

Axelrod told ABC's "Good Morning America" the Obama administration reacted quickly to the disaster. "We had the Coast Guard in almost immediately," he said.

Obama has sent Homeland Security Secretary Janet Napolitano, Interior Secretary Ken Salazar and EPA Administrator Lisa Jackson to Louisiana to assess the worsening situation as the equivalent of 5,000 barrels a day (about 200,000 gallons) seeps from the uncapped well into Gulf waters. BP wants to burn off the fast-moving oil slick but high winds have complicated operations.

On Thursday, Sen. Bill Nelson (D-Fla.) introduced legislation to stop Obama from moving forward on any plan to consider new leases for oil drilling in expanded areas of the Outer Continental Shelf. In a letter, Nelson urged the president to call a halt to all test wells and exploratory activities in coastal waters until the cause of the BP blast is known and understood.