The US claims that it has won a World Trade Organisation (WTO) case against Mexico, with a disputes panel ruling a 20% tax on Mexican soft drinks manufactured with imported high-fructose corn syrup broke global commerce rules.

Drinks made with Mexican cane sugar are exempt.

The 2002-imposed tax decimated US exports of the syrup to Mexico by last year to 6% of their pre-tax levels. The WTO panel found the tax discriminated against foreign suppliers, breaking the organisation's fair trade principles.

US Trade Representative Rob Portman said: "This is an important win for our industry. Mexico needs to eliminate this tax as soon as possible."