Nitin Desai, chair of the Internet Governance Forum (IGF), set up by the UN, warned that concerns over the net's future could lead to separation, reports the BBC.
"People are concerned about whether the system we have now will also work five years from now," he said.
Mr Desai was speaking at a conference in London to discuss the net.
The conference was organised by Nominet, the UK body in charge of domain names ending .uk, ahead of the first-ever Internet Governance Forum, a global gathering of stakeholders in Athens later this month.
The internet was increasingly being shaped by companies and organisations at the "edges" and not by government, public sector bodies and regulators, he said.
This was concerning some countries who wanted more involvement in the development of the net.
"These are the reasons these entities - government and private sector - feel they need to be reassured that the system they are relying on is secure, safe and reliable - that they cannot be suddenly thrown out of that system by some attack," said Mr Desai.
He said the Chinese government was concerned that users still had to type webpage addresses using Latin characters even when the pages were in Chinese.