Washington (CNN) -- The Obama administration made public all information available throughout the Gulf of Mexico oil spill, White House Press Secretary Robert Gibbs said Thursday in response to a preliminary report that criticized how it handled the disaster.





"This was an unprecedented environmental disaster met with an unprecedented federal response which prevented any of the worst-case scenarios from coming to fruition," Gibbs told reporters when asked about the report made public the previous day. "When we had information, we gave it to the public."





According to the working paper released Wednesday from the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, the administration vastly underestimated the tens of thousands of barrels of oil pouring into the Gulf after the April 20 oil rig explosion that caused the disaster, despite contrary information from scientists using better methodologies.





The explosion claimed 11 lives and led to more than 60,000 barrels of oil being spewed into the Gulf daily for almost three months.





According to the working paper, the White House Office of Management and Budget squelched higher worst-case estimates accepted by government officials, preventing the public from hearing them.





In addition, the commission staff sharply criticized later White House estimates that 75 percent of the oil had been scooped up, burned or naturally dispersed, saying an operational tool -- known as the oil budget -- used by responders failed to accurately account for biodegradation and was not peer-reviewed by scientists.





Gibbs acknowledged that some mistakes were made, in particular citing comments regarding the estimated oil dispersal by former White House environmental adviser Carol Browner in one of "hundreds" of interviews she gave.





However, he insisted that the administration worked with the information available at all times, noting that it was impossible to see or measure the oil spill rate in the initial weeks after the explosion.





"Throughout this process, we got better information," Gibbs said. "When the rig exploded and the blowout preventer failed 5,000 feet below the ocean, nobody could see what happened."





The installation of video cameras and other technology improved the ability to estimate the spill flow in ensuing months, Gibbs said. At the insistence of Energy Secretary Steven Chu, the administration required BP to install pressure monitors to provide the "best available data on the flow rate," he added.





The commission working paper said the government's low estimates of oil flow from the spill, as well as the apparent underestimation of how much oil remained in the Gulf, "created the impression that it was either not fully competent to handle the spill or not fully candid with the American people about the scope of the problem."





Gibbs echoed federal officials who say the low flow-rate estimates did not negatively affect their operations to stop the oil spill, describing the overall effort as the "most robust federal response that we've ever seen" to such an accident.





However, the 29-page report said: "Even if responders are correct, however, loss of the public's trust during a disaster is not an incidental public relations problem. The absence of trust fuels public fears, and those fears in turn can cause major harm, whether because the public loses confidence in the federal government's assurances that beaches or seafood are safe, or because the government's lack of credibility makes it harder to build relationships ... that are necessary for effective response actions."





The report is considered a working paper. The commission will issue a formal report on January 12, 2011.





The president appointed the commission in June and tasked it with providing recommendations on how to prevent future spills and mitigate the impact of any that do occur. The commission is headed by former Florida governor and former U.S. Sen. Bob Graham, a Democrat, and former Environmental Protection Agency administrator William K. Reilly from the Republican administration of President George H.W Bush.





Rep. Edward Markey, D-Massachusetts, chairman of the Select Committee on Energy Independence and Global Warming, said BP was providing too-low figures for the oil flow in effort to escape liability.





"Low-balling the flow rate numbers was BP's attempt to hide both the truth and
What did Gibbs said?
"This was an unprecedented environmental disaster met with an unprecedented federal response which prevented any of the worst-case scenarios from coming to fruition,"
question: What did Gibbs said?, answer: "This was an unprecedented environmental disaster met with an unprecedented federal response which prevented any of the worst-case scenarios from coming to fruition,"