WARREN, Ohio (AP) — Republican presidential candidate John McCain, a day after flatly rejecting the idea of a taxpayer bailout for American International Group Inc., said Wednesday that the government had been ‘‘forced’’ into proposing an $85 billion loan to the nation’s largest insurer.

McCain appeared to soften his opposition to the bailout proposed by the Treasury Department, treating the plan as a necessary evil to protect ordinary Americans with finanical ties to AIG — and asserting that such a financial collapse should not be allowed to happen again. He also called for an investigation to uncover any wrongdoing.

‘‘The government was forced to commit $85 billion,’’ McCain said in a statement. ‘‘These actions stem from failed regulation, reckless management and a casino culture on Wall Street that has crippled one of the most important companies in America,’’ McCain said in a statement.

‘‘The focus of any such action should be to protect the millions of Americans who hold insurance policies, retirement plans and other accounts with AIG,’’ he said. ‘‘We must not bail out the management and speculators who created this mess. They had months of warnings following the Bear Stearns debacle, and they failed to act.’’

Although he is stepping up criticism of government regulators as he seeks the presidency, McCain has long favored a reduction in corporate regulation. A similar free-market thinker, former Sen. Phil Gramm of Texas, who led the Senate Banking Committee in Congress, has been an adviser to the campaign.

McCain himself had a hand in economic matters as a member of the Senate Commerce Committee, which he once chaired. His campaign has noted that McCain was heavily involved in telecommunications regulation and deregulation.

McCain said in an interview that he didn’t want the government to bail out AIG. ‘‘But there are literally millions of people whose retirement, whose investment, whose insurance were at risk here,’’ he said in an interview with ‘‘Good Morning America’’ on ABC. ‘‘They were going to have their lives destroyed because of the greed and excess and corruption.’’

Elaborating on the charge of corruption, McCain said that many Wall Street executives had claimed ‘‘everything’s fine, not to worry’’ and that Congress and regulators had paid no attention. ‘‘All of them were asleep at the switch,’’ he said, and went on to blame special interests and lobbyists as well.

Asked for specific examples of corruption regarding AIG, senior McCain campaign adviser Steve Schmidt offered none.

‘‘Well, at this hour, when you look at the situation, it is still muddled and unclear,’’ Schmidt told The Associated Press. ‘‘But it is clear that the system has been corrupted.’’

McCain repeated his call for a high-level commission, on the order of the one that investigated the Sept. 11 attacks, to review the economic troubles on Wall Street. But when asked by ABC for examples of what he would do to deal with the current problems, McCain cited only the proposals he offered well before the crisis emerged — no tax increases, affordable health care and energy alternatives among them.

Barack Obama’s campaign dismissed the idea of a commission. ‘‘The last thing we need is a commission to study a problem that everyone but John McCain knows is the result of the failed economic policies he has championed for the last 26 years,’’ Obama campaign spokesman Tommy Vietor said in a statement.

In the ABC interview, McCain called the financial crisis ‘‘one of the most severe crises in modern times,’’ yet on Monday morning he had maintained his oft-stated position that ‘‘the fundamentals of our economy are strong.’’ For that he drew withering criticism from his Democratic opponent and others. By afternoon, with the markets falling amid other bad financial news, McCain was using a more dire tone.

In two new television ads Wednesday, McCain asserts that he is the right leader to keep Americans’ savings safe.

‘‘Enough is enough,’’ McCain says in one of the commercials. ‘‘I’ll meet this financial crisis head on. Reform Wall Street. New rules for fairness and honesty. I won’t tolerate a system that puts you and your family at risk. Your savings, your jobs — I’ll keep them safe.’’

In a second ad, McCain criticizes Obama as offering only ‘‘talk and taxes’’ as solutions. Obama himself taped a two-minute commercial Tuesday in Colorado in which he speaks directly to American voters about the country’s economic problems.

The early morning release of McCain’s ads and their rapid production — one was taped during a 10-minute stop at a home in Tampa, Fla., on Tuesday — highlight his efforts to claim the high ground on a subject he has acknowledged is a weakness.