US and South Korean negotiators wrangled for a third day yesterday over a free trade agreement, but the US side said a deal is still possible before a weekend deadline despite slow progress.

"I think the deal is possible," said US Trade Representative's Office spokesman Steve Norton.

Both sides have said the talks could go up to the deadline at 7:00 am on Saturday (Seoul time), the last working day of the week in Washington.

The deal must be submitted to Congress next Monday for a 90-day review if it is to be passed while President George W. Bush still has the authority to "fast-track" trade legislation.

"We are ready to stay overnight on Friday," a South Korean trade official told AFP on condition of anonymity.

"It is possible for both sides to talk until the last moment," Norton also said the talks may extend past midnight tomorrow," added the South Korean official.

Seoul officials say there has been no significant progress so far on differences, especially over farm products.

Tug of war

"The tug of war is continuing and both sides are tough," South Korea's Assistant Agriculture Minister Min Dong-seok was quoted by Yonhap news agency as saying.

Min was holding separate talks with the US chief agricultural negotiator, Richard Crowder.

On Tuesday the US side demanded a written commitment from Seoul that it would fully open its market to US beef but South Korean officials said the demand was rejected.