WASHINGTON - THE United States said on Thursday a WTO ruling backs US sanctions against the European Union in a long-running dispute over the bloc's ban on beef from hormone-treated animals.

US Trade Representative (USTR) Susan Schwab said the World Trade Organisation had concluded that the US did not violate its WTO obligations by maintaining additional duties on certain EU products.

The EU claimed it had come into WTO compliance by amending its ban on beef from animals treated with growth-promoting hormones.

'Today's Appellate Body report is significant for the WTO dispute settlement system as a whole,' Ms Schwab said in a statement.

The report 'confirms that WTO members that are subject to additional duties for failing to bring themselves into compliance with the WTO's rulings and recommendations must do more than simply claim compliance in order to obtain relief from such duties,' she said.

The Appellate Body also concluded that because a previous finding by a WTO panel 'made certain legal errors in its analysis of the scientific basis for the EU's amended ban, the question of whether the EU's amended ban is WTO-consistent remains open,' the USTR office said in the statement.

'We very much welcome these conclusions,' Ms Schwab added.

The USTR's office said that because of the WTO report, 'there is no need to remove those duties'.

The dispute over the EU ban on beef from animals administered certain growth-promoting hormones dates back to 1996.

The United States argues that the hormones at issue 'have long been recognised as safe' in the US and other countries, and by the international organisation charged with reviewing them for safety.

In 1996 the US filed a challenge to the EU ban on beef imports from cattle that had been administered certain growth-promoting hormones.

In 1999, after an unsuccessful appeal by the EU, the WTO Dispute Settlement Body authorised the US to impose sanctions against the EU in the amount of US$116.8 million (S$172.7 million) per year.

The US consequently raised tariffs on a some European products that year.

The EU amended its ban in 2003, claiming that the ban now complied with WTO requirements, and challenged the continued application of additional US duties.