Scott Morrison will tell key Asian and Pacific leaders Australia will stick with free trade and the World Trade Organisation despite a push to undermine it.

The prime minister will address the Asia Pacific Economic Cooperation meeting in Port Moresby, immediately before Chinese President Xi Jinping and United States Vice President Mike Pence.

It's understood there is a push from some nations to go harder in opposition to the WTO, rather than try to reform it.

But Morrison will tell APEC Australia is standing by the organization, rather than letting big countries dictate trade terms to smaller countries.

"I know there are legitimate questions around trade arrangements," Morrison said.

"But the solution to perceived unfair trade practices is more likely to be found around the negotiating table than it is in re-building a tariff wall.

"Australia will continue to advocate for trade disputes to be resolved by negotiation and within WTO rules.

"We want to strengthen and improve the WTO and we will continue to pursue liberalisation wherever we can," said Morrison.

Morrison so far does not have a meeting scheduled with President Xi but relations with China continue to thaw despite concerns about growing Chinese influence in the Pacific.

Vice President Pence says the US vision for the region was about "collaboration, not control".

"Empire and aggression have no place in the Indo-Pacific - this is a region where every nation large and small must be permitted to prosper and thrive," he said.

President Xi wrote an article for PNG local media and said China's relations with Pacific countries would be centred on mutual respect and common development.

"China will work with Pacific island countries to brave the wind and waves and set sail for a brighter future in their relations," Xi wrote.

In a joint meeting with Japanese Prime Minister Shinzo Abe in Darwin, Morrison also won Japan's support for reforming the WTO.