South Korea warned the United States Tuesday that a final make-or-break round of free trade talks could break down unless Washington stops pushing to open up the local rice market.

"The deal could collapse if the United States sticks to demands that we cannot accept, such as rice," Trade Minister Kim Hyun-Chong told a meeting of ruling party legislators before the talks went into their second day.

The two countries must complete negotiations by Friday but South Korean negotiators have said they will ignore the deadline rather than accept an unpalatable deal.

Kim said any deal on a free trade agreement (FTA) should reflect South Korea's economic interests "in a balanced manner."