United States beef imports into South Korea were slated to resume yesterday after a deal was reached on April 18 to fully open the market to all US beef.
However, on Wednesday the US Trade Representative Office received reports that Korea would temporarily delay implementing the market access.
"The Korean government received many more public comments than expected," says Gretchen Hamel of the USTR Office.
"We understand that the South Korean government will need to take more time to review these comments."
The delay came as a complete surprise to National Cattlemen's Beef Association economist Gregg Doud.
"It's really a shock, because on Tuesday the discussions were that everything was up and running and ready to go," Mr Doud says.
"There actually is a Korean group of auditors here and those discussions went well and so this whole thing comes as quite a surprise."
Reports indicate that party politics in the South Korean parliament are playing a role in the situation.
South Korea's main opposition party lost control of the assembly in April's elections, but remain in a lame duck session until the new session begins in June.
Guesses as to how long the delay will last range from a few days to several weeks.
South Korean Agriculture Minister Chung Woon-chun told parliament he thought a week to 10 days would be needed.