J.P. Morgan Chase & Co. Chief Executive James Dimon called the bank's $2 billion loss a "terrible, egregious mistake

J.P. Morgan Chase & Co. Chief Executive James Dimon called the bank's $2 billion loss a "terrible, egregious mistake" that will tarnish the firm's reputation.

Speaking on NBC's "Meet the Press," Mr. Dimon appeared to concede that his ability to push back against proposed government regulations will likely be diminished, acknowledging that the trading loss came at a "very unfortunate, inopportune time" as regulators are still crafting rules governing banks' trading activities.

Mr. Dimon, whose firm emerged from the financial crisis relatively unscathed, has emerged as a leading opponent of regulations he says have harmed the financial system and the economy, including the Dodd-Frank financial overhaul written to regulate Wall Street.

Mr. Dimon has been particularly critical of the so-called Volcker rule, named after former Federal Reserve chairman Paul Volcker, which prohibits banks from trading with their own funds. The rule is a central plank of Dodd-Frank. Wall Street critics have charged that the crisis was worsened by banks' making overly aggressive bets.

The Volcker rule was spearheaded in Congress by Sens. Carl Levin (D., Mich.) and Jeff Merkley (D., Ore). In a separate interview on "Meet the Press" Sunday, Sen. Levin said J.P. Morgan will "lose their battle in Washington to weaken" regulations curbing banks' ability to trade with their own capital.

Sen. Levin focused on language in the Volcker rule draft proposal, crafted by five regulatory agencies that would let banks hedge trades on a "portfolio" basis, meaning a bank could make trades that aggregate risks across the firm as a whole, rather than only on a particular trading desk.

Sen. Levin contends banks could use that provision to make large bets, while describing them as hedges against risk.

"We have to be very careful that the regulations are not undermined by this huge effort to weaken the rule by putting in a huge loophole, which is called portfolio hedging," Sen. Levin said. The final version of the Volcker rule, which is still being drafted, is expected to be released by regulators later this year.

In a separate "Meet the Press" interview recorded before J.P. Morgan disclosed its losses last week, Mr. Dimon said the economic recovery has been "too slow" in part due to "this huge regulatory push" by the federal government.

The interview put in focus the executive's frayed relations with his Democrats on Capitol Hill. Mr. Dimon, who has long been a supporter of that party, said he'd call himself "a barely Democrat now."

Mr. Dimon pinned the blame for what he described as harmful rhetoric and regulations on Democrats. "I've gotten disturbed at some of the Democrats' behavior, anti-business behavior, the sentiment, the attacks on work ethic and successful people," Mr. Dimon said. "I think it's very counterproductive."

His comments come amid heightened scrutiny of J.P. Morgan's trading activities in the wake of its trading loss. The Securities and Exchange Commission is reviewing disclosures related to the trades and are focusing on whether the firm revealed the loss to investors soon enough. Read More