The prime minister flies into Canberra on Tuesday after a quick trip to Thailand.

He is expected to convene a meeting of cabinet ministers on Melbourne Cup day to sign off on extra drought relief, with a funding announcement due within days.

Mr Morrison was in Bangkok to attend the East Asia Summit.

On the sidelines of the major regional meeting, he attempted to thaw frosty relations with China during a meeting with Premier Li.

The meeting came after many months of diplomatic tensions over Beijing's human rights records, attempts at foreign interference, and the detention of Chinese-Australian writer Yang Hengjun.

"There's an honest acknowledgement that we're two pretty different countries," Mr Morrison told reporters on Monday.

"We're a liberal democracy and they're a communist party state. We're not seeking to adopt their system, and they're not seeking to adopt ours."

China also came under fire from the United States and India during the East Asia Summit.

US national security adviser Robert O'Brien used a speech to accuse Beijing of intimidating smaller nations by militarising the resource-rich South China Sea and seeking to control the global trade route.

India also raised much stronger concerns than usual about Beijing's actions in the South China Sea during a meeting of regional leaders.

Heads of the 18 nations involved expressed concerns about North Korea's ballistic missile launches, Rohingya refugees and the Rakhine State, according to an official read-out.

Australia also joined the world's largest trade pact during the Bangkok summit, with 15 countries agreeing to the Regional Comprehensive Economic Partnership.

The deal will cover almost half the world's population and promises to bring stability to the Indo-Pacific.

As expected, India did not sign up, because of concerns about opening its markets to China.

"India has significant outstanding issues, which remain unresolved," the nations involved said in a statement.

"All RCEP participating countries will work together to resolve these outstanding issues in a mutually satisfactory way. India's final decision will depend on satisfactory resolution of these issues."

The remaining 15 countries want the deal finalised by November next year, allowing time for "legal scrubbing" to take place.

Mr Morrison flagged his intention to ratify a separate Indonesia-Australia free trade agreement during a meeting with Joko Widodo, cementing plans to visit the country early next year.

He also discussed a January trip to India with Prime Minister Narendra Modi.

Australian Associated Press