Banning state-owned Chinese firms from buying local resources companies would jeopardise foreign investment in Australia, Trade Minister Simon Crean says.

Nationals senator leader Barnaby Joyce wants Chinalco's bid to buy a stake in Rio Tinto blocked on the grounds that allowing a state-owned firm to invest locally would create a future dispute with an emerging superpower.

Mr Crean dismissed Senator Joyce's argument, arguing that a ban on a Chinese sovereign wealth fund buying into an Australian resources company would discourage other countries from investing locally.

"What happens when we get banned in other countries," Mr Crean told Sky News.

"If it's good enough for us to ban one country, why won't another country say to us `look we were thinking of investing in your country but look, you've put this ban on'.

"I understand the concerns that people have. We've got to try and address those concerns but we shouldn't be cowered by them."

Senator Joyce said while he wasn't opposed to Chinese investment in Australia, he had concerns with a Chinese government-run enterprise owning a stake in Rio Tinto.

"If they are both the owner of the minerals in the ground in Australia and the purchaser of the minerals in China, then they'll do what any accountant will tell them to do and that is to get the cheapest price possible," Senator Joyce said.

"And if you try to dispute that, you've turned a corporate issue into a diplomatic one with an emerging superpower."

Senator Joyce has appeared in a national television campaign against Chinalco's bid to buy a $27.69 billion stake in resources giant Rio Tinto.

Treasurer Wayne Swan announced last month the government would not endorse aspects of China's Minmetals' $2.6 billion bid for OZ Minerals if a South Australian copper and gold mine near a weapons-testing range was included in the deal.

But the Rudd government has indicated the rejection of the OZ Minerals takeover would not affect the Chinalco offer for Rio Tinto.