A divided G20 summit highlights the need for Malcolm Turnbull to decide how he's going to deal with US President Donald Trump on areas of difference, Labor believes.
Opposition foreign affairs spokeswoman Penny Wong says the communique from the world leaders meeting in Germany produced an unusual outcome in splitting over climate change.
It acknowledges Mr Trump's decision to pull out of the global agreement on climate action, struck in Paris in 2015, but says "the leaders of the other G20 members state the Paris Agreement is irreversible" and are committed to meeting their emission reduction targets.
"The division is made clear, the disagreement is made clear," Senator Wong told ABC TV on Sunday.
"And regrettably for Australia, the US position on climate runs counter not only to our interest but I think to the weight of global opinion."
Senator Wong said Australia needed to be clear with the Trump administration about differences and energetically engaging with the US over them, whether on climate or in relation to North Korea or South-East Asia.
But she doesn't think the prime minister has worked out how to deal with that yet.
"This has been Mr Turnbull's problem: he hasn't known whether to glide over differences, whether to be up front or whether to not say anything," she said.
"It is important for us to recognise that no matter what the US does, they are a leader. It is always a question of what sort of leadership they are providing."
Labor was pleased to see the G20 acknowledge the importance and benefits of open markets and maintain the commitment to fight against protectionist measures.