New York: UN Secretary General Ban Ki-moon said he was encouraged by 'positive discussions' in Berlin on North Korea's nuclear programme and urged the resumption of six-party talks.

The UN did not elaborate on the discussions.

In Seoul, US chief negotiator Christopher Hill Friday denied a North Korean report that US and North Korean negotiators had reached an agreement following three days of face-to-face talks in Berlin this week.

North Korea's official Korean Central News Agency (KCNA) quoted a spokesperson saying North Korea had reached a "certain agreement" with the US.

A spokesman at the UN headquarters here Friday said Ban welcomes reports of active preparations for the next round of the six-party talks on denuclearisation of the Korean peninsula. He was encouraged in particular by the recent positive discussions in Berlin between the Democratic People's Republic of Korea and United States negotiator".

The six-party talks, among the US, Russia, China, Japan and the two Koreas, are slated to resume sometime in February.