Disagreement over the access of U.S. carmakers to the lucrative South Korean automobile market was the main reason the two countries failed to advance a long-stalled free trade pact, U.S. officials said.

Mike Froman, an economic adviser to U.S. President Barack Obama, said there were a number of other sticking points, but autos had been the main obstacle to a deal.

“Autos is a major outstanding issue and we’ve spent a great deal of time on autos in the last four days and will be continuing to work on that issue as we go forward,” Froman told reporters after a meeting in Seoul between Obama and South Korean President Lee Myung-bak that had been dominated by trade.

U.S. Trade Representative Ron Kirk said restrictions on U.S. beef had been another hurdle, but denied the failure to get an agreement represented a kind of failure for Obama.

“We’ve made good progress. These are very tough agreements to get done. I like to think we’re closer to the end,” he told the reporters. (Reuters)