The United States will tell key leaders to push against "empire and aggression" in Asia and the Pacific as concerns about China's influence grow.
US Vice President Mike Pence will issue the call on Saturday when he speaks at an Asia-Pacific Economic Cooperation meeting in the Papua New Guinea capital Port Moresby.
Prime Minister Scott Morrison will also address the meeting and may also meet with President Xi Jinping as relations with China continue to thaw.
"I think we're moving into a new phase there, which I think is very good for Australia," Mr Morrison told ABC radio on Friday.
"Our positions have not changed, our consistency will be maintained but the relationship, I think, is very positive."
President Xi received a lavish welcome in Port Moresby, being the first of the APEC leaders to arrive for the annual summit.
He is due to announce a major aid and investment package to benefit Pacific nations including Fiji, Vanuatu, Samoa, Micronesia, the Cook Islands, Tonga and Niue.
"President Xi Jinping is a good friend of Papua New Guinea," PNG Prime Minister Peter O'Neill told reporters.
Competition for influence in the Pacific between China and Western allies Australia, New Zealand and the US, will provide a strong undercurrent at the APEC summit.
With US President Donald Trump not attending, Vice President Pence - who will be staying in Cairns and flying into PNG daily - will underline Australia's role in the Indo-Pacific and call for greater economic development.
Speaking in Singapore, Vice President Pence said the US vision for the region was about "collaboration, not control".
"The United States seeks an Indo-Pacific where every nation is free to follow its own path, pursue its own interests, where the seas and skies are open to all engaged in peaceful activity and where sovereign nations grow stronger together," he said.
"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."
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," the Chinese leader wrote.
Before the APEC summit, Mr Morrison announced details of Australia's "pivot" to the Pacific region including a $2 billion financing facility and $1 billion for Australia's export financing agency Efic.
