Prime Minister Tony Abbott has given his clearest signal that climate change will not be front and centre on the G20 agenda when Australia hosts the forum later this year.

Mr Abbott, who leaves on Wednesday for a 12-day trip to meet world leaders in Indonesia, France, Canada and the US, could be challenged by President Barack Obama about the exclusion of climate change after the US announced major steps this week to slash carbon emissions.

Speaking to reporters in Canberra, the Prime Minister played down the significance of climate change as part of the G20 program and said the November summit was primarily an ''economic meeting'' to discuss finance and trade.

President Obama's plan to cut emissions from power plants by 30 per cent on 2005 levels is seen as a firm commitment by the US in the lead-up to international climate talks in Paris next year.

China will also for the first time set a limit on its emissions announcing an absolute cap would be included in the country's next five-year plan starting in 2016.

Australia, by contrast, is increasingly viewed as becoming disengaged from debate on climate policy.

With the announcement of the US plan this week, Labor and the Greens criticised the government for ''sending Australia backwards while the rest of the world moves forward''.

Mr Abbott's talks with President Obama will cover economics and trade, but the dramatic acceleration in US climate policy has prompted speculation there will be pressure from the President for the inclusion of climate change as a major economic issue on the G20 agenda.

Both the US and the European Union have previously expressed disappointment at the exclusion of the climate policy on the G20 agenda.

Mr Abbott said on Wednesday that other international meetings were more appropriate for discussing global action to cut greenhouse gas emissions.

''It's also important to ensure that these international meetings don't cover all subjects and illuminate none,'' he said.

''It's important we keep a strong and focused agenda if we are to achieve anything significant and different international meetings tend to focus on different subjects.

''The G20 is essentially an economic meeting. There are other meetings such as the East Asia summit which are essentially security discussions and then of course there is the UN for the discussion of climate change.''

But Mr Abbott agreed that the efficient use of energy was an important economic issue.

''So I'd be surprised if climate change doesn't come up as part of the G20 but the focus of the G20 will overwhelmingly be our economic security, our financial stabilisation, the importance of private sector-led growth,'' he said.