Lee Zeldin, a former US congressman from New York, has committed to Trump's campaign pledges of boosting US energy dominance and rolling back environmental regulations enacted under President Joe Biden.

The Republican president-elect has dismissed climate change as "a hoax" and revived his old claims during his election campaign that it is of no concern, as he promised to expand drilling for oil and gas.

But Zeldin told the Senate Environment and Public Works Committee he believes climate change is "real" and that Trump's comments should be seen as worry over the price tag of green policies.

"I think that he's concerned about the economic costs of some policies where there's a debate and a difference of opinion," Zeldin said.

In a podcast interview in August, Trump claimed falsely that "the oceans in 500 years will raise a quarter of an inch" and "the oceans will rise an eighth of an inch in 355 years."

"You know, they have no idea what's going to happen. It's weather," he said.

Some environmental groups have voiced concerns over Zeldin's nomination -- noting his loyalty to Trump -- but he appears to be on a glide path to confirmation, with strong Republican support.

Democrat Sheldon Whitehouse asked Zeldin about the environmental impact of carbon dioxide emissions from burning fossil fuels.

"I don't sit before you as a scientist," Zeldin said, although he later acknowledged that carbon dioxide traps heat.

He said he would prioritize clean water and air but did not offer any detail on his plans to address climate change.

He also touted his record of bipartisan efforts on environmental issues in Congress and said he hoped to work with lawmakers from both parties in his new post.

"It's been so motivating to see the tremendous talent stepping up to serve in the EPA, I couldn't be more excited to partner with the EPA team nationwide," he said.