The parties to the six-way nuclear talks are hammering out a deal to provide energy aid to North Korea, if it takes initial steps to scrap its nuclear program.

Delegates spent Sunday, the fourth day of talks, in bilateral and trilateral discussions on the amount and timing, as well as how to share responsibilities for the energy aid among the other five countries.

Chief South Korean negotiator Chun Yung-woo told reporters that there was no progress in the discussions, adding that he didn't expect an agreement in Sunday's negotiations.

Chinese Foreign Ministry spokesman Qin Gang told reporters that the six countries differ widely on the economic and energy aid issues.

Chief U.S. negotiator Christopher Hill said that having working groups handle unresolved issues would be more appropriate, adding that the main point of contention is one paragraph in the proposed agreement.

He urged delegating thorny issues to specialists, saying that chief negotiators should focus on main agenda items such as North Korea's initial steps to give up its nuclear ambitions.