Billboards and bus stands across the city of 22 million are spelling out the benefits of global trade, international cooperation and economic growth.

The Chinese slogan "One Belt, One Road" dominates headlines. State-controlled social media is pumping out rap and rock songs, and even a bedtime children's story, in an attempt to explain what this actually means.

The shorthand version is the Belt and Road Initiative (BRI), Xi's grand vision to build a modern-day Silk Road connecting China overland to Europe, and by cargo ship to Asia and beyond.

This will require improving the infrastructure of developing nations to cater for the trains and ships that will ply goods on these new trade routes.

More eye-catching than the slogan is the funding for the grand plan, up to $US1 trillion ($1.3 trillion), on offer. Two banks, the China Development Bank and the Export-Import Bank of China, have already loaned $US200 billion to BRI projects, executives said.

The Industrial and Commercial Bank of China will invest $US337.2 billion in 412 projects.

Strategic rivals have criticised the project as an attempt by China to buy influence in developing countries, who risk losing control of key infrastructure like ports under heavy debt burdens.

China hit back this week, saying a debt limit had been set for each country applying for BRI loans, and "most" projects would generate sufficient cashflow.

Officials have also rejected criticisms that the huge infrastructure program is simply designed to generate more work for idling Chinese construction firms.

The Sunday forum is the government's attempt to reshape the narrative that One Belt, One Road is China's vision alone, and overcome Western suspicion.

The leaders of rivals Japan and India won't be there. Washington confirmed on Friday it will send a delegation.

Russian President Vladimir Putin is the headliner among the Eastern European and Central Asian heads of state attending.

From Australia's neighbourhood, Indonesian President Joko Widodo, Malaysian Prime Minister Najib Razak, Philippine President Rodrigo Duterte and Myanmar's State Counsellor Aung San Suu Kyi will be in Beijing, as will the leaders of Fiji, Vietnam and Sri Lanka.

Malcolm Cook, a senior fellow at ISEAS Yusof Ishak Institute in Singapore, said there has been considerable interest in the economic benefits to South-east Asia.

"Most South-east Asian countries are simultaneously seeking closer economic relations with China and more outside assistance with infrastructure development," Dr Cook said.

"In India and Japan, there is more scepticism and the strategic concerns likely weigh more heavily."

Trade Minister Stephen Ciobo is the only Australian minister attending. While Mr Putin will bring an entourage of Russian companies, no Australian companies have been invited.

Australia is yet to officially sign on to BRI, despite China's desire for infrastructure projects to turn the Northern Territory into an arable food bowl to be a part of its maritime silk road. A Chinese company, Landbridge, already owns the Darwin port.

"Australian participation is to put further meat on the bone for BRI. Given the strong relationship between Australia and China, it is important Australia is there to learn more," Mr Ciobo said.

He said Australian companies have great experience in "financing, designing and the construction of major infrastructure".

"There are complements between northern Australia and Belt and Road, but they are separate initiatives."

Former trade minister Andrew Robb, who signed the Free Trade Agreement with China, and is now a director of Landbridge, will also attend along with representatives of 130 countries. He is "disappointed" the Australian government is yet to sign up to BRI.

Mr Robb led a "volunteer" delegation of Australian banks and services companies to Beijing in October, and is convinced there are joint-venture opportunities for Australian businesses to build the hospitals, schools and aged care services that China wants to provide along the new trade routes.

In the Pakistani' port of Gwadar, one of the flagship projects, a new hospital donated by China's Red Cross opened this month, across the road from a new school also donated by China.

Mr Robb said scepticism it is all a strategic power play by China has been an issue in Australia.

He said it will be important for the weekend summit to show BRI is not just rhetoric, but real, with a pipeline of projects Australian companies can join.

"There has been a lot of pressure from the US to not engage in the [BRI], like the pressure that came on for the Asian Infrastructure Investment Bank," he said. (Australia joined the bank a year later).

"China admits there is no way they can roll out this pipeline alone. They need partnerships around the world.

"If China is responsible for materially improving the quality of life in 60 countries, there is a fair chance they will have more influence in those 60 countries. There is nothing stopping the US from spending the same money."