WASHINGTON -- President Barack Obama defensively and sometimes testily insisted on Thursday that his administration, not oil giant BP, was calling the shots in responding to the worst oil spill in the nation's history.
"I take responsibility. It is my job to make sure this thing is shut down," Obama declared at a news conference in the East Room of the White House. The Gulf of Mexico oil spill dominated the hour-long session.
He called the spill, now in its sixth week, an "unprecedented disaster" and blasted a "scandalously close relationship" between Big Oil and government regulators.
Obama announced new steps to deal with the aftermath of the spill, including continuing a moratorium on drilling permits for six months. He also said he was suspending planned exploration drilling off the coasts of Alaska and Virginia and on 33 wells under way in the Gulf of Mexico.
The president's direct language on being in charge of the spill, which he repeated several times, marked a change in emphasis from earlier administration assertions that, while the government was overseeing the operation, BP had the expertise and equipment to make the decisions on how to stop the flow.
Taking control carried its own political risks for Obama, because any failure to stop the gusher would then belong to the president. But Obama could suffer politically if his administration was seen as falling short of staying on top of the problem or not working hard to find a solution.
"The American people should know that from the moment this disaster began, the federal government has been in charge of the response effort," Obama said. He was reacting to criticism that his administration had been slow to act and had left BP in charge of plugging the leak.
Obama said many critics failed to realize "this has been our highest priority."
"My job right now is just to make sure everybody in the Gulf understands: This is what I wake up to in the morning, and this is what I go to bed at night thinking about. The spill."
As he spoke, oil BP worked furiously to pump mud-like drilling fluid into the blown-out well.
It was an untested procedure to plug the blown-out oil well. It seemed to be working, officials said Thursday, even as new estimates showed the spill has surpassed the Exxon Valdez in Alaska as the worst in U.S. history.