Noted Wall Street irritant Sen. Elizabeth Warren slammed President Donald Trump 's new steps to ease some financial regulations, arguing that he showed hypocrisy after a populist campaign.

The order Trump signed starts a review of the Dodd-Frank financial reform act, the bank industry rules passed after the 2008 financial crisis that he heavily criticized on the campaign trail. The second action was expected to delay a rule intended to require financial advisors to give customers advice that is in their best interest.

While it is not immediately clear how those actions would affect banks' behavior, Warren argued that they were a setback. The Massachusetts Democrat and other key party colleagues quickly signaled that they would use Trump's moves as political ammunition in a Congress that has become increasingly tense in the early days of Trump's presidency.

"Donald Trump talked a big game about Wall Street during his campaign — but as president, we're finding out whose side he's really on. Today, after literally standing alongside big bank and hedge fund CEOs, he announced two orders — one that will make it easier for investment advisors to cheat you out of your retirement savings, and another that will put two former Goldman Sachs executives in charge of gutting the rules that protect you from financial fraud and another economic meltdown," Warren said in a statement.

Warren criticized Trump for appearing with executives like JPMorgan Chase CEO Jamie Dimon at an economic advisory meeting Friday. She also referred to Trump Treasury nominee Steven Mnuchin and economic advisor Gary Cohn, who both worked at Goldman. Trump repeatedly targeted the firm on the campaign trail as evidence of wealthy elites' influence on the financial system.

Trump's order directs the Treasury Department to review whether existing laws and regulations follow what Trump identified as "core principles" of his administration. The president directed the Treasury secretary to file a report within 120 days on possible regulatory changes or legislative recommendations.

The order said the review will focus on several broad administration goals that largely relate to his campaign pledges to reduce government involvement in business and make American companies more competitive. It said Trump aims to "empower Americans to make independent financial decisions," "prevent taxpayer-funded bailouts" and create economic growth through "more rigorous regulatory impact analysis."

The order also outlined goals to "enable American companies to be competitive with foreign firms" and "advance American interests in international financial regulatory negotiations." Trump's White House also wrote it wants to "make regulation efficient, effective and appropriately tailored" and "restore public accountability with federal financial regulatory agencies."

Bank stocks popped following Trump's move.

Supporters of the Dodd-Frank reforms, which were designed to make the financial system safer, say they increased the stability and liquidity of key institutions. Critics, many in the financial industry, have said it makes it more difficult to lend and harms smaller banks.

Trump said before the meeting with executives that he wanted to cut "a lot" of Dodd-Frank.

Senate Minority Leader Chuck Schumer, D-N.Y., also ripped the move, saying Trump is letting big banks "write the rules of the road."

More From CNBC

• Top News and Analysis
  

• Latest News Video
  

• Personal Finance