US Edition Kai Eide told The Daily Telegraph he would also like to see a person-by-person review of detainees held in the Bagram American military prison to see if prisoners could be released.
The Norwegian diplomat said the two measures were aimed at slowly building momentum for a political process of talks with the insurgents.
Mr Eide, special representative of the UN Secretary-General, was speaking before an ambitious peace plan to be launched by President Hamid Karzai at a conference in London.
Mr Karzai's international backers are expected to support a reintegration plan offering money, land, jobs, training and development to fighters and their villages who lay down their arms.
Mr Eide said money was needed to reintegrate insurgents, but warned it was insufficient without political talks with their leaders.
He said: "I really do believe that the reintegration process by itself is not enough. It has to be a parallel political process.
"I think the time has come to initiate some confidence building measures in order to see if it's possible to create some momentum in that political process at the strategic level.
"One is the delisting from the sanctions list. To start on a person-by-person basis to take people off that list, to get that process going, I think that would have an important psychological effect and it would have a political effect."
The UN's al-Qaeda and Taliban sanctions committee drew up the blacklist under resolution 1267 a decade ago when the Taliban regime was isolated for harbouring Osama bin Laden.
It includes former ministers, diplomats, governors and officials, as well as their al-Qaeda guests.
Several have been subsequently killed, but others are at large and thought to remain influential in the insurgency.
Those on the list, including Taliban leader Mullah Mohammad Omar, have their assets frozen, are blocked from international travel and are subject to an arms embargo.
Removal would require a request from the Afghan government followed by a vote from the five permanent members of the Security Council.
Mr Eide said he was not calling for the removal of Mullah Omar, or his most senior lieutenants, but added "if you want relevant results you have to talk to relevant people with authority".
Last week The Daily Telegraph disclosed a briefing document from the Afghan government suggested Taliban leaders could also be offered "potential exile in a third country". In return they would renounce violence, accept the Afghan constitution and sever all ties with al Qaeda.
Mr Eide said: "We have seen in the past that these kind of moves, these kind of confidence-building measures are often the way you start a peace process, the way you test the water to see if it is possible to get the process under way."
His comments came after a US strategy document from Hillary Clinton said Taliban commanders should be taken off military "kill or capture" lists if they chose to negotiate.
The US State Department's Afghanistan and Pakistan regional stablisation strategy released last week said: "Commanders contemplating reintegration will receive credible security guarantees so that they need not fear that while they negotiate with one entity (eg the Afghan Government) they will be detained or killed by another (eg counter-terrorist operatives)."
David Miliband, the Foreign Secretary, told the BBC on Sunday the Afghan government had to bring the Taliban into the political system and the "vast bulk" were not aligned with al-Qaeda.
He said: "If you want people to be in their communities defending their communities rather than attacking their government, you need first of all to make sure that they're secure in their communities, secondly that they have something to do and thirdly that they have a voice in their communities."