The United States last night said it would postpone collecting tariffs on certain European Union imports until the World Trade Organisation completed a review of the penalties in a trans-Atlantic banana row.

But US special trade negotiator, Mr Peter Scher said EU exports - valued by Washington at $520 million (€477 million) - would be liable for the penalties from yesterday and these would be charged retrospectively.

The US Trade Representative Office said the US customs service beginning would require importers of EU goods, including about £3 million in Irish exports - mainly pork products - to post bonds to cover the threatened duties from yesterday.

European Union Trade Commissioner, Sir Leon Brittan said the latest US move was "unacceptable and unlawful".