A strong China is an asset, not a threat, to the global economy but the rising giant is unlikely to overtake the United States as the world's biggest economy in the next century, former World Trade Organisation (WTO) head Mike Moore said today.

Moore, who is also former New Zealand prime minister, said he has "never feared a strong China but I fear a weak China" because this could lead to more poverty and economic uncertainties in the world.

"A strong China and India are healthy and will strengthen the world economy and security order," he said in an address at an Asian economic conference here.

"But the United States, for the next 100 years, will remain the world's strongest ecoomy if it keeps its immigration policy open and attracts the best minds. I don't see that (China overtaking the US). China is not as big as California."

But he said China remained a key engine for regional and global growth and although its economy was cooling down, it would still play a significant role.

"China growing at six to seven percent a year will still be a significant growth machine," he said.

A regional consumer

"I don't think it is a regional monster at all. I think it's a regional consumer. China's imports went up by more than her exports in the last 12 months. She's energy hungry, she's part of the global supply line and China's growth is powering growth in so many areas."

Moore said a "bipolar regional world has emerged, with a successful China and growing competitors like India and this is good for all of us."

"I don't see China's growth as replacing the growth of Malaysia, Singapore or the United States. It complements it. It just means you have to move into high-value areas and they are doing it. Every criticism you hear of China is what you heard of Japan 20 years ago," he said.

"All this talk 10 years ago of China elbowing us out and we'll all be sitting around flipping hamburgers is just nonsense."

Moore also hit out at some rich nations protesting the move to outsource operations to the developing world, calling it "nonsense" adding that outsourcing reflected the success of globalisation and would enrich poor nations.