Mr Turnbull welcomed Prime Minister Shinzo Abe to Sydney on Saturday as part of the Japanese leader's latest regional tour, widely seen as an attempt to shore up regional solidarity before Mr Trump ushers in a new era of unpredictability.

The two men will play a role in shaping how Mr Trump – a foreign policy novice with little experience in the Asia Pacific – views and approaches the region.

After an informal stroll along Sydney's south head heritage trail, the pair donned the jackets and ties for an official bilateral meeting at Kirribilli House.

When the cameras left they quickly took off the jackets though – a sign of comfortable informality as much as the soaring mercury.

America's engagement with the region was a key topic for the talks, particularly given Mr Trump's aggressive rhetoric over China.

The future of regional trade – including the ambitious Trans-Pacific Partnership deal that Mr Trump has promised to tear up on his first day in office – and ongoing regional tensions in the South China Sea also figured prominently.

For Mr Turnbull, the meeting promised valuable insights given Mr Abe was the first world leader to meet with Mr Trump after his election. Mr Trump will officially take office on January 20 after his shock win over Hillary Clinton.

Mr Turnbull and Mr Abe also touched on North Korea and Mr Turnbull did express Australia's disappointment about Japanese whaling.

Japan has sent its whaling fleet to the Southern Ocean with the intention of killing more than 330 minke whales for what it describes as scientific research.

The hunt has resumed despite an international court ruling in 2014 in a case brought by Australia that declared Japan's whaling to be illegal.

After the meeting, the leaders gave remarks but took no questions.

"The relationship between Australia and Japan is closer, stronger and more constructive than ever," Mr Turnbull said.

"We look to Japan as Japan looks to Australia as a reliable and trusted partner."​

Sunday marks two years since the Japan-Australia free trade agreement entered into force.

Trade Minister Steve Ciobo says the deal has given Australian businesses a competitive advantage that is driving exports, generating jobs and growing the economy.

But the TPP could do even more good.

"Australia very firmly believes the TPP holds significant benefits for all 12 countries that have signed up to it. It is our earnest hope we will continue to see the ratification of the TPP by all 12 countries," the trade minister said.

After Australia, Mr Abe will visit Indonesia and Vietnam.