U.S. President Donald Trump appears on stage at a rally in Harrisburg, Pennsylvania, U.S. April 29, 2017. REUTERS/Carlo Allegri

WASHINGTON (Reuters) - U.S. President Donald Trump said he was actively considering breaking up big banks, Bloomberg Television reported on Monday.

Trump’s comments could give a push to efforts to revive the Depression-era Glass-Steagall law that separated commercial lending from investment banking. Reviving such a law would require an act by Congress.

“I’m looking at that right now,” Trump said on Monday in an interview with Bloomberg News in the Oval Office. “There’s some people that want to go back to the old system, right? So we’re going to look at that.”

While campaigning for president, Trump had expressed support on the campaign trail for a “21st-century Glass-Steagall.”

White House spokesman Sean Spicer told a news briefing that Trump had expressed interest in the issue and had been briefed on it by Treasury Secretary Steven Mnuchin but was not ready to discuss it publicly.

“We’re not at a point where we’re ready to roll out details of that yet,” Spicer said. “He is actively looking at options and considering things.”

One of Trump’s top economic advisers, Gary Cohn, director of the National Economic Council, reiterated Trump’s support for the concept during a private meeting with lawmakers on April 6, a White House spokesperson told Reuters.

U.S. stocks sharply pared gains on Monday after Trump’s comments and the S&P 500 bank index dropped nearly 1 percent before rebounding.