The federal government expects United States President Donald Trump to walk away from the Paris climate agreement, but Prime Minister Malcolm Turnbull and his senior ministers insist Australia will not follow suit - despite pressure from the Coalition backbench.

Australia's chief scientist, Alan Finkel, said the exit of the US from the global accord on reducing greenhouse gas emissions was "a blow, but not fatal", while Mr Turnbull told Parliament "we are committed to the Paris agreement, and we're on track to meet our targets".

"That's our commitment, affordable, reliable energy, and meeting our emissions reduction targets in accordance with the Paris treaty."

Mr Trump is expected to announce at 5am Australian time on Friday the US will withdraw from the agreement, despite the urgings of European leaders, the United Nations and business giants including Facebook, Tesla, Apple and Google.

The US is the world's largest economy and second-largest carbon emitter and its expected withdrawal from the global deal, which aims to reduce nations' emissions and limit global temperature rises, would be a major blow.

Five MPs on the Coalition backbench - Ian Goodenough, Eric Abetz, Ian MacDonald, Tony Pasin and environment committee chair Craig Kelly - told Fairfax Media the government should reassess being part of the Paris agreement if Mr Trump did withdraw the US.

Mr Goodenough said Australia needed to meet its obligations but "in the event that the USA withdraws from the Paris agreement then I believe that Australia should reassess its position and engage in dialogue with the international community, and not take unilateral action without consultation and national debate".

Mr Kelly welcomed the prospect of the US withdrawing from the treaty and added that "Australia has to do what is best for us".

Senator Abetz said the Finkel review of climate policy, which is currently underway and due to be handed to government on Friday week, should take into account the US decision and that Australia should not slavishly pursue its emissions reduction targets if it hurts employment or households.

Mr Pasin and Senator MacDonald echoed those sentiments.

Taken together, the comments once again underscore the political fault line that has run through the Coalition on how to tackle anthropogenic climate change since 2009.

Environment Minister Josh Frydenberg said that what Mr Trump did was a matter for the US, but the Turnbull government was fully committed to the deal.

However, a key member of Mr Turnbull's inner circle, Industry, Innovation and Science Minister Arthur Sinodinos, told a Senate hearing that if Australia withdrew, that could lead to other countries taking "sanctions" against Australia for shirking its part of the global task.

"We make a lot of agreements and we make them as a small country because it's in out interest," he said.

"It's in our interest to get stability around climate issues and to minimise the cost of adjusting to the world as it may be in 40 or 50 years time and we have to be seen meeting our agreements.

If Mr Trump honours his election campaign to do so, the US will join just Syria and Nicaragua as the only three countries not part of the 195-country accord struck in 2015.

Senator Sinodinos said: "We don't quite know where Trump will go, we think the money is on him withdrawing."

Unlike its predecessor treaty, the Kyoto Protocol, the Paris deal was intended to be non-binding but compelled countries to set emissions reductions targets post 2020 and meet them.

Australia set a target to reduce emissions by 26- to 28 per cent below 2005 levels by 2030 as part of its Paris commitment.

The US target is a 26- to 28 per cent reduction from 2005 levels by 2025 under the Paris deal.

Dr Finkel said a US departure would not derail the global effort.

"If, as is likely ... America under President Trump decides not to confirm its commitment to the Paris accord, that is one country out of nearly 200 ... one very, very important country, so that's a blow to the accord but it's not fatal," he told a Senate estimates hearing.

Shadow environment spokesman Mark Butler said Mr Kelly's comments were cause for concern.

"I think what this indicates is a worrying sign that there will be a debate within the Coalition that perhaps Australia should follow the US out of the Paris climate agreement if indeed Donald Trump pulls the US out of it," Mr Butler told Sky News.

Follow us on Facebook