SEOUL - PYONGYANG'S promised declaration of its atomic activities will be a step on the road to a nuclear-free Korean peninsula but it will take years to complete the journey, analysts say.

Some believe the secretive communist regime will never surrender the atomic weapons it has been developing for decades, even though it appears willing to sacrifice the ageing plutonium-producing Yongbyon complex.

The North was scheduled later on Thursday to deliver the declaration of its nuclear material and programmes - but not weapons - to China, which hosts six-nation disarmament negotiations that began in 2003.

The declaration will be 'a positive development but there is a long way to go. We need to continue building on that,' said Mr Daniel Pinkston, senior analyst with the International Crisis Group.

'In my view, it will take years and not months,' he told AFP.

The final phase of a six-nation denuclearisation pact 'will have even more difficult issues on the table' in addition to a new government in Washington, he said.

This last phase envisages the hand over of all weapons and fissile material in return for diplomatic ties with the US and Japan and a formal peace pact.

The declaration, which is almost six months overdue, will list all nuclear material, facilities and programmes, US chief negotiator Christopher Hill said this week.

But weapons will be dealt with in the next phase, he said.

The key element, he added, will be a verifiable figure for how much bomb-making plutonium has been produced at Yongbyon over the years.

US Secretary of State Condoleezza Rice, under pressure from conservative sceptics in Washington, has stressed the need for verification.

The North will reportedly admit a 37kg plutonium stockpile, less than the 40 to 50kg that US intelligence officials have calculated.

The North, which staged a nuclear test in October 2006, has for months been disabling its key plants at Yongbyon under US supervision.

Given the 'slow - albeit important' progress so far, the task of finding a final verifiable resolution will be handed over to the next US administration, said analyst Tong Kim in a recent article.

Mr Kim, a visiting professor with Seoul's University of North Korean Studies, estimated that under the current diplomatic process 'it would probably take at least three or four more years of 'action for action' engagement with the DPRK (North Korea) to dispose of its last nuclear weapon.'

A mutual lack of trust is one of the toughest hurdles, he said.

'North Korean leader Kim Jong Il would likely make his final decision to give up nuclear weapons only when he feels comfortable to trust the United States.'

Mr Kim said the North 'is still carefully calculating the benefits and the risks at every step of moving toward the presumed final destination of denuclearisation.'

The North is receiving energy aid worth hundreds of millions of dollars in return for the declaration and disablement. It will also be removed from a US terrorism blacklist if the declaration can be verified.

Andrei Lankov, an associate professor at Seoul's Kookmin University, believes the regime will not surrender its weapons.

'The nuclear weapons are important for both deterrence and blackmail,' he wrote in a recent analysis.

'Without the nukes the... leaders will feel vulnerable to a foreign attack, and also will not be able to extract sufficient aid from the international community.

'Since they cannot make their economy really efficient, they badly need this aid. In order to receive it, they have to maintain tension and also fabricate crisis, to be paid for solving it.' -- AFP