Transportation Secretary Pete Buttigieg says he's taking steps to impose stronger regulations on freight trains hauling toxic chemicals, such as the one that derailed and exploded into flames near East Palestine, Ohio, earlier this month, forcing thousands of people to evacuate their homes and raising environmental and health concerns.

He's also calling on Congress to "untie" the agency's hands in regards to legislation that weakened the Department of Transportation's ability to enforce certain safety and accountability rules.

Buttigieg accused the rail industry of employing "vigorous resistance" to increased safety measures, which he says has thwarted efforts to strengthen tank cars and mandate a better braking system on trains that carry volatile fuels, chemicals and other toxic substances.

"Profit and expediency must never outweigh the safety of the American people," Buttigieg said on Monday. "We at USDOT are doing everything in our power to improve rail safety, and we insist that the rail industry do the same — while inviting Congress to work with us to raise the bar."

Safety advocates say has Buttigieg been slow to respond to the rail disaster and the DOT has been slow to take up new rail safety regulations in the two years he's been in the office. Buttigieg tried to shift the blame to the industry, suggesting its heavy lobbying led Congress to limit the DOT's ability to act.

Republicans, especially, have called Buttigieg's response to the disaster lacking. Buttigieg has pushed back, saying Republicans in Congress have watered down his agency's rail safety efforts.

Buttigieg reiterated the need for stronger railroad safety rules and enforcement power in a Tuesday interview with Morning Edition.

"The investigation into root causes is being led by the National Transportation Safety Board. NTSB is independent, with good reason, and we will know more when they issue their final report," Buttigieg said. "But it is not too soon to push toward a change in how industry approaches safety. And that's exactly what we're calling for today."

He also said that people in East Palestine are "right to be concerned."

He pointed to actions the federal government is taking, from the Environmental Protection Agency testing the air, water and soil to the Centers for Disease Control sending public health teams to the community. The EPA on Tuesday said it would take control of the cleanup and train operator Norfolk Southern would have to pay the costs.

"This is an all-hands-on-deck matter where you have multiple federal agencies partnering with state government and local authorities to get these residents everything that they need," Buttigieg said. "And that support is going to continue."

Buttigieg wants newer tank cars, better brakes and higher fines

Buttigieg, who has faced some criticism for not visiting the crash site, says he has stayed away to allow the NTSB take the lead on the investigation of the cause and for emergency management to focus on the immediate response. He says he hopes to visit the site sometime in the future, but no date has been set.

Speaking to reporters on Monday evening, Buttigieg said he wants rail companies to speed up their phasing in of sturdier, more puncture-resistant tank cars that carry volatile or toxic substances. The DOT mandated the new tank cars be in use and older, weaker ones to be phased out by 2025. But Congress delayed that new tank car deadline until 2029.

Buttigieg also wants Congress to raise the maximum amount the DOT can fine railroads for safety violations. He says fines right now are so low that he's concerned the big railroad corporations just write them off as a cost of doing business.

"The maximum fine we can issue, even for egregious violations involving hazardous materials resulting in the loss of life, is just over $225,000," he said. "For a multibillion-dollar rail company posting profits in the billions every year, it's just not enough to have an adequate deterrent effect."

Buttigieg added that the DOT is considering revising how it classifies certain toxic and volatile chemicals. While the derailed Norfolk Southern train was considered one carrying hazardous materials, it was not considered a "high hazard flammable train," or HHFT, which requires certain safety protocols be followed.

And he says he wants to move forward on requiring trains carrying such hazardous materials be equipped with a higher level, electronically controlled braking system. In 2015, the DOT enacted a rule requiring electronically controlled pneumatic brakes on trains with more than 20 HHFT cars, but Congress mandated a cost benefit analysis be conducted before it could take effect, and then in 2017, the Trump administration repealed the rule.

"We can't treat these disasters as inevitable or as a cost of doing business," Buttigieg said. "There's a window of opportunity with Congress now after what happened in East Palestine that I do not think existed before, and we aim to use that window of opportunity to raise the bar" on safety.