China needs to be more responsible as it gains global influence and avoid flexing its muscles in disputes with smaller countries over issues like the South China Sea, US President Barack Obama has warned as he arrives in China on the first leg of his final tour of Asia.

In an interview with CNN, Obama, who will meet President Xi Jinping at a G20 summit in China, said that US supported the peaceful rise of China but that Beijing had to recognize that "with increasing power comes increasing responsibilities", according to excerpts released on Friday.

"If you sign a treaty that calls for international arbitration around maritime issues, the fact that you're bigger than the Philippines or Vietnam or other countries ... is not a reason for you to go around and flex your muscles," Obama said.

"You've got to abide by international law."

China, a signatory to the UN Convention on the Law of the Sea, recently lost an arbitration dispute over the South China Sea.

A court in the Hague found that China had no historic title over the waters of the South China Sea and had infringed on the rights of the Philippines.

China has repeatedly warned that it will not recognize any adverse ruling from The Hague's arbitration court. Beijing boycotted the hearings at the Permanent Court of Arbitration, saying that it does not have jurisdiction to decide the dispute.

Obama said that Washington had urged Beijing to bind itself to international rules and norms to help build a strong international order.

Obama is scheduled to touch down in Hangzhou, a city in eastern China that is hosting this year’s G20, on Saturday.

He is due spend much of the day with Xi with the pair expected to make a high- profile joint declaration on climate change in which the US and China will announce plans to formally ratify the Paris climate agreement.

"We know the two sides have been discussing this for a few months," said Li Shuo, the Beijing-based senior climate policy adviser for Greenpeace East Asia. "If they do that just one day before the G20 it will inject momentum for other G20 countries to follow suit."

Collaboration between the US and China on the fight against global warming has proved one bright spot in an otherwise fraught relationship.

Relations have soured since Xi became president in early 2013 and began pushing a far more assertive and nationalistic foreign policy, notably in the South China Sea where Beijing has sought to affirm its rights over disputed territory through a controversial artificial island building campaign.

Despite those simmering tensions, Nick Bisley, an Asia expert at La Trobe University in Australia, said he did not anticipate any major public spat between Washington and Beijing during Obama's farewell trip to China.

"My sense is it will be a bit of a love-in," he said. "There is no benefit at all, certainly from an American side, to stoking this one unnecessarily and I don't see why if you are Beijing you benefit from picking a fight with the Americans unnecessarily."

Instead Bisley predicted Beijing would be focused on using the two-day G20 summit to show China had become "a top tier player" in global affairs.

"Part of the theater of this whole (G20) thing will be about illustrating China's arrival - the world comes to China's door and doesn't quite kowtow but does the next best thing. And that general message would be crowded out by an overt bust up between the Chinese and the Americans over the South China Sea."