Just days before the Prime Minister is due to meet president Barack Obama, a senior US Democrat has criticised Tony Abbott's stance on climate change as making Australia a "behind-the-scenes lagger" on global efforts to tackle the problem.

The vexed issue is expected to be discussed when the two leaders sit down for talks on Thursday (US time) in Washington.

Long-serving Californian Democrat Henry Waxman, regarded as one of the most powerful Democrats in the US, told ABC1's 7.30 program that the Australian Government's plan to repeal the carbon pricing scheme is a "mistake".

"As I understand it, Australia will go from being one of the great leaders in the world in tackling this problem, to one of the great laggers in addressing efforts to reducing the pollution that is threatening the planet that we're living on," he said.

Last week the Obama administration unveiled new regulations requiring the power sector to cut emissions by 30 per cent on 2005 levels by 2030 - one of the strongest actions ever taken by the US to combat global warming.

Mr Abbott has likened the measure to his own government's "direct action" policies, but Mr Waxman says the Australian policy "doesn't sound anything like what President Obama is proposing".

"What President Obama is proposing ... is much closer to the existing Australian law and that's why I hope that Australian law is not reversed," he said.

He says the Australian "direct action" policy, where companies bid in reverse auctions to win taxpayer funding for programs to cut their emissions, is a voluntary system "that never worked anywhere".

"It would be a serious mistake for Australia to leave that policy and go to one that's voluntary," he added.

Before his swing through the United States, Mr Abbott met his Canadian counterpart and fellow conservative Stephen Harper, who shares the Australian Prime Minister's opposition to carbon trading systems.

Mr Waxman has warned both countries are "out of sync" and "at odds" with international moves, particularly in the US and Europe.

"Rather than being leaders, they're going to be behind-the-scenes laggers - they're going in the wrong direction," he said.

The congressman also said Mr Obama would "look forward" to climate change being on the agenda at November's G20 leader's summit in Brisbane - something Mr Abbott is thought to be resisting in favour of other economic issues.

"I hope that Australia will not turn its back on its leadership role and become a drag on what we all need to be doing around the world," he said.

"We can't discuss the economy without talking about energy and environmental protection."

Mr Waxman will retire this year after 39 years in Congress.

He lists as one of his political "highlights" securing damning testimony from tobacco company bosses in 1994, who swore under oath that smoking was not addictive and did not cause diseases.

"When you hear people denying the science of climate change it's so reminiscent to me of the tobacco company scientists," he told 7.30.

Mr Waxman's comments came as Clive Palmer confirmed that his Palmer United Party would support legislation to scrap the carbon tax.