When a South Korean official asked about the offer during a meeting of liaison officers in the North's border city of Kaesong, a North Korean official only said he understood what the South is talking about, the spokesman said.

"Consultations are still underway over the methods and schedules for a joint railway inspection," Baik said. "We have not received the North's position yet."

The railway survey is part of a summit agreement between the leaders of the Koreas in April to modernize and eventually reconnect rail systems over their border, a project aimed at fostering reconciliation on the Korean Peninsula.

The field study was scheduled to take place in August, but the UNC disapproved it, citing procedural problems. The disapproval was seen as reflecting Washington's displeasure with its possible violation of sanctions.

Over the weekend, the UN Security Council decided to grant a sanctions exemption, allowing the once-suspended project to go ahead.

"We will do this in a way not to cause any concerns or problems with regard to sanctions," the spokesman said.

A joint railway inspection, if held, would mark the first of its kind in about a decade. In 2007, the two Koreas held a test train operation on a 412 km-long railway linking Kaesong to Sinuiju in the North.

The spokesman said that there have been delays in some cross-border projects but dismissed concerns, saying that most exchanges and cooperation continue without much trouble.

Meanwhile, he said that the two Koreas are currently in talks to allow Korean-Americans to meet their relatives in the North on the occasion of a possible future reunion of families separated by the 1950-53 Korean War.

South and North Korea held weeklong reunions of hundreds of separated families at Mount Kumgang in late August in accordance with an inter-Korean summit agreement in April.

In September, their leaders agreed to discuss through Red Cross talks about allowing them to have video reunions and exchange video messages. (Yonhap)