Australia is receptive to exploring commercial opportunities China's new Silk Road presents to the country's businesses, but any decisions would remain incumbent on national interest, Trade Minister Steven Ciobo says.

Key points: Collaboration on Belt and Road initiative contingent on Australia's national interest

Collaboration on Belt and Road initiative contingent on Australia's national interest US wary of North Korea attending the Beijing summit to unveil Silk Road plan

US wary of North Korea attending the Beijing summit to unveil Silk Road plan Chinese President Xi Jinping pledged $124 billion in funding toward the initiative

The One Belt One Road initiative is Chinese President Xi Jinping's signature foreign and economic policy espousing billions of dollars of infrastructure investment linking Asia, Europe, Africa and beyond.

The ambitious plan is to build a vast network of new trade routes across the globe, multiple high-speed rail networks to penetrate Europe, massive ports across Asia and Africa and a series of free-trade zones.

Mr Ciobo said there were a lot of opportunities for Australian businesses to be involved in China's new initiatives.

"We see much merit in the Belt and Road initiative, we see opportunities for collaboration, but we take decisions about initiatives in Australia on the basis of what is Australia's national interest," he said.

"Although the northern Australia initiative is separate to the Belt and Road Initiative, there are clearly complementarities there so we can share knowledge and we can share experience for the benefit of both nations."

The plan was unveiled at a two-day summit in Beijing in which 28 world leaders and representatives from another 70 countries attended.

Opening the summit on Sunday, Mr Xi pledged $124 billion in funding toward the initiative.

Mr Ciobo also condemned North Korea's latest firing of a ballistic missile early on Sunday, but would not be drawn on whether North Korea's attendance at the summit — at Beijing's invitation — sent the wrong message at a time when the world was trying to pressure Pyongyang over its repeated nuclear and missile tests.

"There [are] more than a thousand delegates that are here," he said.

"This is an event that has been organised by the Chinese to focus on the Belt and Road Initiative."

Western diplomats worry the scheme expands China's global influence ( AP: Ng Han Guan )

The United States sent a diplomatic note warning to China on Friday that North Korea's attendance at the summit could affect the participation of other countries, casting a shadow over what is Beijing's biggest diplomatic event of 2017, two sources with knowledge of the situation said.

Denis Richardson said China is keeping a watchful eye inside Australian communities. ( ABC News: Nicholas Haggarty )

Some Western diplomats have expressed unease about both the summit and the plan as a whole, seeing it as an attempt to push Chinese influence globally.

On Friday, Australia's most senior defence department official, departing Secretary of Defence Dennis Richardson, said China was spying and exerting "unreasonable" influence over Chinese communities and media in Australia.

His warnings followed similar concerns raised by former diplomat Chen Yonglin, who last year warned the number of Chinese spies and agents working in Australia was growing.

ABC/Reuters