Sen. Elizabeth Warren on Friday accused the acting head of the Consumer Financial Protection Bureau of undermining President Donald Trump’s stated push to make credit cards more affordable, according to a letter obtained exclusively by CNBC.

In a letter to acting CFPB Director Russell Vought, Warren, D-Mass., noted that in the last year the agency has dropped a rule limiting credit card late fees, sided with lenders in lawsuits over deceptive practices and paused enforcement actions against the industry.

Earlier this month, Trump demanded in a social media post that U.S. banks voluntarily cap credit card interest rates at 10% for a year. When they didn’t, Trump this week called on lawmakers to pass legislation on the issue.

“I spoke with President Trump last week and told him that Congress could pass legislation to cap credit card rates, if he would fight for it,” Warren wrote in her letter to Vought.

“While Congress considers legislation to address the issue, your own actions are directly undermining the President’s stated goals,” she wrote. “Under your leadership, the CPFB has taken steps to make it easier—not harder—for big banks and credit card companies to rip off Americans.”