North Korea and the United States disagreed on the opening day on Monday of six-way working talks on how to end Pyongyang's nuclear programmes while South Korea offered aid to the struggling North in return for progress.
Seoul would be more flexible in the talks on the North Korean nuclear crisis and was ready to provide a security guarantee in return for nuclear dismantlement, South Korean Foreign Minister Ban Ki-moon told Reuters in an interview.
North and South Korea, the United States, Japan, Russia and China began two days of working-level talks to lay the foundation for a third round of complex discussions this week on the crisis.
Reclusive Pyongyang held out the prospect of a "road map" for freezing or dismantling its nuclear programme if the United States and others said what they would give in return, South Korea's Yonhap news agency said.
The United States rejected the offer, saying the communist state must first come up with a detailed plan for a freeze leading to eventual nuclear dismantlement, it quoted a South Korean official as saying.
Officials from several parties involved have cautioned that scant progress can be expected at the senior-level talks, aimed at ending a 20-month stand-off between the United States and North Korea over Pyongyang's nuclear ambitions.