When talking about Fonterra's overseas expansion, most newspaper inches are devoted to China and South America - a developing world where New Zealand's professional farming polish can work up a good profitable shine.

And yet the richest and most developed nation on the planet might hold some of the biggest opportunities - welcome to America.

Fonterra USA's Waiuku born and bred president Martin Bates says the division is involved in partnerships and activities generating turnover of US$2.5 billion ($3.2 billion) a year and probably contributes revenue of US$1.3 billion to the group result.

"I can easily see that we can double that business in three to five years," Bates says. "And the biggest opportunity is not the import side of things, it's working in the US and leveraging our technologies and those things in there."

Fonterra will officially open its new North American headquarters and a development centre in Chicago later this month.

Fonterra USA has five core parts - importing commodities such as casein and milk proteins, value add ingredients for product functional and nutritional attributes, exports, a small brands business and a joint venture with co-operative Dairy Farmers of America called DairiConcepts which is mainly domestic focussed with manufacturing of milk proteins and cheese powders.

The company has a marketing relationship with Dairy America - an association of nine producer-owned dairy co-operatives - to supply skimmed milk powder to the global traded market.

The development centre has been moved from a smaller operation located in Mexico and is an extension of the research and development undertaken in Palmerston North.

Fonterra works with customers who could be making products including cheese or yoghurt on areas such as reducing formulation costs, nutritional claims or probiotics.

The cultured products category in the US is quite small and there is a big gap in comparison to the yoghurt market in Europe, while the customers are after pretty much the same thing - more health and nutrition, he says.

"So in the next 10 years there's going to be a huge amount more yoghurt consumed in the US."

Cheese demand is expected to grow by 2-3 per cent a year and is already the equivalent of five times what the total New Zealand milk production could produce if it were all used for making cheese.