Western Australia Premier Colin Barnett said on Tuesday that “doors are open” to investment from China, the state's largest trading partner.

His remarks came days after he kicked off a visit to China in a bid to lure new investment to revive Western Australia's troubled Oakajee Port and Rail development.

“Chinese investors are becoming more careful and I think it is a good thing,” Barnett told reporters in Beijing. “But Chinese investment is still increasing.”

The Chinese government was targeted as a major potential investor for the proposed $6 billion development.

The project will build a rail network to connect mines to a new deep-water port at Oakajee, north of Geraldton. The plan was shelved last year after Japanese backer Mitsubishi scaled back funding.

Barnett hailed Western Australia's cooperation with Chinese State-owned enterprises over the past two decades, saying these “good business partners” have invested a large amount of money there.

“Whoever wins the next federal election, I would hope they would relax rules on foreign investments by State-owned enterprises,” said Barnett. Australia will hold a general election in September.

About 80 percent of investment by China's State-owned enterprises in Australia is in Western Australia, and 66 percent of Australia's total exports to China are from this state with a population of just 2 million.

Barnett said he was told by many Chinese officials that priority was given to the so-called rebalancing of Chinese economy – not so rapid growth but a concentration on improving the environment, and particularly air quality.