Talks on breaking down global trade barriers entered the final stretch here Saturday, with ministers of World Trade Organisation (WTO) countries struggling to overcome continuing discord over farm trade liberalisation and cross-border expansion of services.

With only 24 hours to go before the Dec 18 deadline for completing the WTO negotiations, disagreement still persisted on details of a special trade and aid package for least developed states and further moves to slash tariffs on industrial goods worldwide.

Senior US officials said agreement on many core issues was "within our grasp" but warned that required "sure-footed negotiations" in the coming hours.

Ministers must be "willing to stretch ... and bridge their differences", said US Deputy Trade Representative Peter Allgeier.

Delegates said pressure was growing on EU to agree to a 2010 deadline for the total elimination of farm export subsidies.

Allgeier said if the EU ceded on the 2010 end date, the US was ready to abolish its export credit programme and accept tougher disciplines to ensure US food aid does not displace commercial sales of farm products.

"We are prepared to take on obligations," said Allgeier.

The EU has long said that it will only take on a firm commitment on ending farm export subsides if the US accepts a comparable pledge on ending food aid programmes, which Brussels claims often distort local agricultural markets in developing nations.

The EU is also demanding that Australia, Canada and New Zealand impose tougher disciplines on their state-run commodity cartels.

The US, Brazil and India, joined by many other WTO members, have said repeatedly that success in Hong Kong hinged on agreement on eliminating farm export subsidies.