WASHINGTON — U.S. Treasury nominee Scott Bessent on Thursday faced sharp questions from both Democrats and Republicans on tax policy, tariffs, China, Russia sanctions and the future of an IRS tax filing system that Republicans have called to be cut.

And in turn, Bessent defended President-elect Donald Trump’s economic policies and proposals.

Trump’s nominees to lead the Environmental Protection Agency, Lee Zeldin, and the Interior Department, former North Dakota Gov. Doug Burgum, also had confirmation hearings.

Bessent sat in front of the Senate Finance Committee for his confirmation hearing, where he told lawmakers that the U.S. faces economic calamity if Congress does not renew provisions of Trump’s Tax Cuts and Jobs Act. He also asserted the Federal Reserve should remain independent of the president’s influence and that U.S. sanctions on Russian oil should be more aggressive.

He was introduced by a fellow South Carolinian, Republican Sen. Lindsey Graham, who said the U.S. needs a treasury secretary “who knows what he’s doing, has the trust of the president and loves his country.” Graham added: “Your ship came in with this guy.”

But Democrats, including Sens. Ron Wyden of Oregon and Michael Bennet of Colorado, expressed frustration that Trump’s promise to extend provisions of his 2017 tax cuts would benefit the wealthiest taxpayers and add to the growing national debt, which has surpassed $36 trillion.

Bennet assailed Bessent for shedding “crocodile tears” over the debt and spending while the Tax Cuts and Jobs Act drove up the debt. “There’s so many things I think you owe the American people after we have seen the catastrophe” from the tax cuts, he said.

Republican Sen. Ron Johnson of Wisconsin also probed Bessent with questions about bringing national spending down to pre-pandemic levels.

In his testimony, Bessent committed to maintaining the IRS’ Direct File program — which allows taxpayers to file their returns directly to the IRS for free — at least for the 2025 tax season, which begins Jan. 27. Republican lawmakers say the program is a waste of money because free filing programs already exist, although they are not popular.

He also called for stronger sanctions on Russia, saying the Biden administration’s sanctions regime isn’t “muscular” enough. “I believe the previous administration was worried about raising U.S. energy prices during an election season,” he said.

Also on Thursday, Zeldin said Americans deserve a clean environment “without suffocating the economy” during his Senate confirmation to lead the Environmental Protection Agency, a department likely to play a central role in Trump’s pledge to slash federal regulations and promote oil and gas development.

It was a mostly friendly hearing that occasionally grew pointed when Democrats questioned Zeldin about climate change, asking what, if anything, Zeldin thinks should be done about a problem that has worsened floods and raised sea levels but that Trump has dismissed.

Democratic Sen. Sheldon Whitehouse of Rhode Island, for example, asked about basic climate science, including what impact carbon dioxide emissions from burning fossil fuels have on the atmosphere.

“I don’t sit before you as a scientist,” Zeldin said. After a follow-up question, he did say that carbon dioxide traps heat.

Trump led efforts to dismantle environmental protections during his first term and has promised to do so again.

Meanwhile, Burgum told a Senate panel Thursday the U.S. can leverage development of fossil fuels and other energy sources to promote world peace and voiced concerns about the reliability of renewable power sources promoted under the Biden administration.

Burgum also said the U.S. needs to make more “baseload” electricity from coal and other sources as it seeks to power data centers for the nation’s tech industry. If confirmed, Burgum would become the chief steward of federal lands.

“This is something that is critical to our national security,” Burgum said. “Without baseload we’re going to lose the AI arms race to China.”

The Republican’s security claims were challenged by Hawaii Democrat Sen. Mazie Hirono, who said military leaders have described global warming as a threat that could trigger instability and wars.

Fossil fuels — oil, natural gas and coal — cause climate change. When they burn, greenhouse gases are released. Asked if he thinks climate change is a problem, Burgum said he believed it’s a “global phenomenon.”

The Interior Department oversees a half-billion acres of federal land and vast areas offshore.