Barack Obama is expecting to discuss climate change at the G20 summit in Brisbane, with the US ambassador to Australia reinforcing the president's message that it is a "critical" issue.
In a wide-ranging address to the National Press Club on Wednesday, in which he also spoke about marrying his partner of 17 years thanks to same-sex marriage laws, ambassador John Berry said the US was raising climate change through its sherpas for the November summit.
"I think we can't lose sight that this is an important issue, it's one the United States will raise in every international forum, it is one we will continue to press on, it is of critical importance, we see not only to Americans but to the world," he said.
Berry said the US wanted other countries to set aggressive renewable energy and carbon reduction goals. Citing the success of global action to fix the ozone layer, he said co-operation could help tackle environmental issues.
"The president believes we can do this without damaging or hurting the economy [and] support the objective of increasing jobs and economic growth. We share that focus point that treasurer Joe Hockey and [Tony Abbott] have, but we also believe consistent with those goals that we can make the advances that will make our future healthier," he said.
The US has set a goal to reduce its carbon footprint by 30% by 2030 and Berry said that, as one of the world's largest polluters, the US had to lead by example.
"Forget the science, rather than argue about that till the cows come home, the worst case if we make these investments is we end up with cleaner air for our children to breathe," he said.
Obama and Abbott differ in their views on the importance of climate change but had an amicable meeting earlier this month in which defence was the focus. The Australian government has not made climate change a priority on the G20 agenda, preferring to focus more on economic issues.
On possible intervention in Iraq, Berry said it should not be the US that asks Australia to send military assets. He said Australia's counsel was valued and the US did not expect the country to be a "yes man".
"It's not for us to ask for assets to be deployed in this area, it's for the Iraqi government and once they do, it is for our independent governments, Australia and the US, to make our own determinations and to do that after we've benefited from our joint counsel together," he said.
Berry also spoke about the impact marriage had on him after being with his partner for 17 years and said same-sex marriage was an issue Australia had to decide for itself.
"I never dreamed that my partner and I would have the privilege and the right to be able to marry in our lifetime ... I have to tell you the day we did I thought after 17 years this would not be anything new, that's a pretty long engagement," he said.
"But both of us said it was so ennobling and sustaining, to have your family and your friends come out and bless and support very visibly our love for each other, and we knew that love was there but we didn't believe it in our hearts as much as we do now, and that sustainment I will take with me to my grave. So it was a critical thing."