President Obama on Tuesday pledged to conduct a "full and vigorous accounting" of what went wrong in the lead-up to the "worst oil spill in U.S. history," vowing to bring "to justice" anyone who may have broken the law. 

The president spoke briefly after holding his first meeting with the co-chairmen of an independent commission investigating the BP spill in the Gulf of Mexico. The administration has tried to take a tough tone against BP while the company struggles to cap the gushing leak. As Attorney General Eric Holder traveled to the Gulf coast to meet with his state counterparts and U.S. attorneys from the region, the president suggested the spill could soon be treated as a criminal matter. 

"If our laws were broken leading to this death and destruction, my solemn pledge is that we will bring those responsible to justice on behalf of the victims of this catastrophe and the people of the Gulf region," Obama said, adding that U.S. laws and policies may have to change in light of the disaster. 

But with the region facing immediate economic and environmental threats, Obama stressed that the administration is continuing to do all it can to mitigate the damage and monitor BP's efforts "minute-to-minute" to cap the leak. He said 17,000 National Guard have been deployed across four Gulf coast states. 

Obama met Tuesday with Bob Graham, a former Florida governor and U.S. senator, and William K. Reilly, a former head of the Environmental Protection Agency - both were tapped to head the independent commission. 

The 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 LLC 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. 

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. 

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

The Associated Press contributed to this report.