Published: Jun 01, 2010 3:00 PM EDT
Updated: Jun 01, 2010 12:00 PM EDT

 WASHINGTON (AP) - President Barack Obama plans to hold his first meeting with the co-chairmen of an independent commission investigating the catastrophic oil spill in the Gulf of Mexico.

Obama was to meet Tuesday with Bob Graham, a former Florida governor and U.S. senator, and William K. Reilly, a former head of the Environmental Protection Agency, with a statement to reporters afterward, the White House said.

In a sign of an increasingly assertive administration role, Attorney General Eric Holder also planned to visit the Gulf Coast Tuesday to see areas affected by the oil spill and to meet with state attorneys general and U.S. prosecutors.

Several senators have asked the Justice Department to determine whether criminal or civil laws were broken in the spill. The Justice Department has told Sen. Barbara Boxer, who heads the Senate's environment committee, that it has ordered BP PLC not to destroy documents that could be relevant in an investigation. Holder was scheduled to receive a Coast Guard tour, then meet with the attorneys general of Louisiana, Alabama and Mississippi and several U.S. attorneys.

The independent commission's inquiry will range from the causes of the spill to the safety of offshore oil drilling and the functioning of government agencies that oversee drilling. The session comes three days after BP said its latest attempt to stop the oil spewing out of a broken well 5,000 feet underwater had failed, and four days after Obama visited coastal Louisiana to assess the situation and assure residents frustrated by the government's response that he is doing everything possible to fix the well.

Amid concern that the worst oil spill in U.S. history could threaten his presidency, Obama has stepped up his public appearances to demonstrate that he is engaged. He held a White House news conference Thursday, focused almost entirely on the oil spill, and followed that with the Gulf visit on Friday.

Tuesday's meeting will be Obama's first with the commission since he named it less than two weeks ago. Obama still must name five members of the commission, which will investigate such issues as what caused the spill, the safety of offshore drilling and operations at the federal agency that grants drilling rights. Obama was not expected to announce those names on Tuesday.

The Gulf oil spill began April 20 when BP's Deepwater Horizon drilling rig exploded off the Louisiana coast, killing 11 workers and rupturing the underwater pipe. In the six weeks since, the government estimates that between 19.7 million and 43 million gallons of crude have poured into the Gulf - affecting beaches, wildlife and the local economy and making it the worst spill in U.S. history.

After BP announced Saturday that its latest attempt to stop the oil, known as a "top kill," had failed, Obama said that disappointing news was "as enraging as it is heartbreaking." It was the latest in a series of failed efforts by the British oil company to shut off the oil flow.

BP will try again as early as Wednesday when it attempts to put a cap on the leaking well so oil can be siphoned to the surface. Graham, a Democrat, served in the Senate from 1987 to 2005 and previously served two terms as Florida governor. Reilly served as EPA administrator under President George H.W. Bush.

Meanwhile, Carol Browner, a top adviser to Obama, said she doesn't want to guess the prospects for success when BP again tries to use a containment cap to control the Gulf Coast oil spill. Interviewed Tuesday on ABC's "Good Morning America," the White House energy and global warming czar said, "I dont want to put odds on it. ... We want to get this thing contained."

Browner said, "everyone, I think, is hoping for the best, but we continue to plan for the worst." She said she's concerned about the impact the hurricane season could have on ending the environmental crisis.