Five Indian states have announced partial bans on the drinks in schools, colleges and hospitals. Southern Kerala state is the first to completely ban their production and sale.

Mr Lavin told the AFP news agency that it would be unfortunate if the loudest voices were those who did not want to treat foreign companies fairly.

'Absolutely safe'

A spokesman for one of the Indian industry federations. Kiran Pasricha, said he hoped US companies would see the row in the context of local politics and would not base their investment plans based on it.

The governments in the states which have banned the soft drinks have said they have taken the step because the drinks pose a health risk.

The ban by the states is the most severe reaction to a report released recently by an Indian non-government organisation, the Centre for Science and Environment.

It said tests carried on samples of the drinks across 12 Indian states revealed dangerously high levels of pesticides.

Both Coca Cola and Pepsi have disputed the report's findings, saying their drinks meet international safety standards.

The Indian Soft Drinks Manufacturers Association has echoed the same sentiment.

"Our products manufactured in India are absolutely safe and meet every safety standard set by food health and regulatory bodies in India and all over the world," it said.

In 2003, the Indian parliament upheld a similar report by the NGO, alleging that soft drinks sold by the two companies in India contained pesticides.

It recommended that India set purity standards for soft drinks.

But three years later, the government is yet to act on the recommendation.