Scott Morrison has warned against the dangers of taking a transactional, "zero-sum" approach to international relations and called for world trade reform on his first visit to London as Prime Minister.
Mr Morrison makes his maiden voyage to the United Kingdom as mass rallies and protests marking the visit of US President Donald Trump clog the streets.
Meanwhile, the UK political establishment is concentrating on the impending departure of British Prime Minister Theresa May after almost three arduous years of failed talks to strike a Brexit deal.
Amid the political chaos in the UK, Mr Morrison warned a gathering of business leaders that the global trading system was under "real and sustained pressure" and that the trade conflict between the US and China was putting the prosperity and living standards of billions of people at risk.
"We must do everything we can to avoid a zero-sum mindset developing, especially when it comes to global trade and commerce," he said in a speech to the Australian-UK Chamber of Commerce on Tuesday.
"And we must guard against the lurch towards a narrow, transactional approach to international relations - where our relationships and the ambitions for the world we share, become nothing more than the sum of our deals."
The prime minister stressed that international relations were not merely economic, but fostered by shared experiences and history.
He used the example of D-Day, where he will be attending a ceremony commemorating the 75th anniversary of on Wednesday, and the Bretton Woods conference in 1944, which has underpinned the post-war liberal economic order.
Mr Morrison said that conference led to the foundation of the World Bank, the IMF and the original General Agreement on Tariffs and Trade and culminated in the establishment of the World Trade Organisation.
He called for reform of the WTO to avoid a further breakdown of international relations into a cold economic transactions.
"The WTO remains the best foundation we have for securing continued prosperity in a fast-changing world; as the Brexit debate in this country demonstrates only too well," he said.
"So we must remain committed to this task - to allow commercial society to flourish - to allow the people in this room - the entrepreneurs, the employers, the risk takers - to make the investment decisions so vital to future prosperity.
"It is critical, therefore, that like-minded countries, including Australia and the United Kingdom, lend their support to WTO reform - to mend, not end, the rules-based trading system."
