Top South Korean and U.S. trade officials failed to agree on the beef issue during two hours of talks in Washington early Wednesday Korean time.

The latest meeting was the third between Trade Minister Kim Jong-hoon and U.S. Trade Representative Susan Schwab.

Before the talks, Kim said a working-level meeting was held to review the feasibility of several proposals offered by the U.S. He vowed to do his best in the negotiations to defuse public concerns over U.S. beef safety.

But after the talks, he said only that additional talks have been set. The two sides will meet again Wednesday night Korean time.

One source says the overall situation is fluid, adding that it’s difficult to predict the result and too early to be optimistic or pessimistic.

But a USTR spokesman said the atmosphere at the talks was “pretty okay,” noting that the two sides focused on technical details.