"We believe (the programme) exists," Kim Man-Bok, the head of the National Intelligence Service, told a closed-door parliamentary committee, according to lawmakers who attended the meeting.

Kim was answering a question on whether the North is operating a highly-enriched uranium (HEU) programme, the lawmakers told Yonhap news agency on condition of anonymity.

US claims that the North has such a programme led to the collapse in 2002 of a previous deal to dismantle its nuclear facilities. A new agreement reached last week in Beijing did not directly address the HEU issue.

Under the February 13 deal reached during six-party talks the North, which conducted its first nuclear test last October, agreed to disable its nuclear facilities in exchange for badly-needed energy aid.

As a first step it will shut down and seal its Yongbyon plutonium-producing reactor within 60 days, admit UN nuclear inspectors and receive 50,000 tons of heavy fuel oil or equivalent assistance in return.

Action to permanently disable the nuclear facilities would be rewarded with up to 950,000 tons of heavy oil or other aid.

Critics say the deal does not immediately address either the North's existing nuclear weapons and plutonium stockpile, or its suspected uranium-based programme, which the communist state has never publicly admitted.

Estimates vary but most experts believe the North has produced enough plutonium to make six to eight nuclear bombs.

The White House said Sunday the Beijing agreement is just the first step "in a long series that includes the complete renunciation of nuclear weaponry and facilities within North Korea."

Under the deal the North must eventually submit a list of its nuclear facilities and programmes, including any uranium-based one.

All rights reserved. © 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.