President Donald Trump and his economic adviser Gary Cohn. Getty Images/Pool

Gary Cohn, the top economic adviser to President Donald Trump and former Goldman Sachs chief operating officer, told lawmakers that he backed a rule that would separate commercial and investment banks, according to a report from Bloomberg.

Bloomberg's Elizabeth Dexheimer reported that Cohn told a private meeting of the Senate Banking Committee that he supported separating the riskier investment-banking side of Wall Street from the consumer-facing lending business.

The answer was prompted by a question from Wall Street critic Sen. Elizabeth Warren, Bloomberg said, citing sources in the room.

Such a move would cause a major realignment on Wall Street. The Glass-Steagall Act, a 1933 law mandating the separation of the investment and commercial banks, was repealed in 1999, leading to a slew of bank mergers. These combined businesses have been blamed by lawmakers and analysts as a contributor to the financial crisis.

The comments seem to fall in line with the thinking of many within Trump's administration. The Republican platform for the 2016 election called for a return of Glass-Steagall, and Treasury Secretary Steven Mnuchin told the Senate Finance Committee during his confirmation hearing that he backed a "21st-century version" of the law.

Neither of those statements, however, came from someone who was the second-in-command at an investment bank like Goldman as Cohn was. According to Bloomberg, many of the lawmakers were surprised at Cohn's comments.

It also runs against initial signals from the Trump administration regarding deregulation of financial institutions. Trump signed an executive order shortly after taking office in February instructing the Treasury Department to look into ways to repeal or roll back the major Dodd-Frank regulations for banks that grew out of the financial crisis.

Cohn did not provide details of any official plan from the White House, according to the report, and it is unclear when the White House would take up the push for reform.