A former US diplomat trying to resolve outstanding peace process issues in Northern Ireland has said the angry reaction to proposals to end Troubles prosecutions has given him a fuller understanding of the plight of victims.

Dr Richard Haass would not be drawn on whether the controversial suggestion by the region's attorney general would be on, or off, the table in forthcoming negotiations with Stormont main political parties.

However, he said he wanted to reassure those bereaved in the conflict that their interests would be an important consideration.

Many relatives of people killed by paramilitaries or state forces in the Troubles reacted furiously to Mr Larkin's proposals, which also included halting further civil proceedings, inquests or state inquiries into conflict related crimes.

Mr Larkin, who insisted a line should be drawn on offences perpetrated before the signing of the 1998 Good Friday peace agreement, met with Dr Haass in Belfast today to outline his ideas.

Afterwards Dr Haass said the attorney general's intervention had served to "crystallise" public and political views on issues related to dealing with the past.

"I thought the scale and the intensity of the reaction was instructive," he said.

Dr Haass said he had personally been impacted by some of his meetings with victims groups.

"I do want to reassure people who either are victims or who are concerned with victims that we have come away from this week with a fuller appreciation of what it is they face and the interest that must be taken into account in this process.

"Speaking personally rather than professionally, it is impossible to come away from these meetings with victims and survivors groups and not be affected.

"This is a political situation sure, but it is also a human situation and it is a personal situation."

While Mr Larkin claimed his suggestion did not amount to an amnesty, its critics have characterised it as one.

As well as being loudly denounced by many victims' relatives, the administrations in London, Belfast and Dublin all distanced themselves from the proposals.

Dr Haass, who was envoy to Northern Ireland between 2001 and 2003 under George W Bush's presidency and is current president of US think-tank the Council for Foreign Relations, has been asked by Stormont First Minister Peter Robinson and Deputy First Minister Martin McGuinness to chair the talks process with an end-of-year deadline to report.

As well as trying to find consensus on the ever emotive issue of the past, he is also bidding to resolve long-standing disputes about parades and flags.

This week he has held more than 25 hours of meetings with delegates that are representing Stormont's five main parties in the talks process. He will return in December to begin full-scale negotiations.

On a fact-finding trip to Derry on Wednesday, Dr Haass was confronted by the sisters of a man killed in the city on Bloody Sunday 1972 by British paratroopers who urged him to reject any notion of an amnesty.

Dr Haass, who is being supported in his work by US foreign affairs expert and Harvard professor Dr Meghan O'Sullivan, will return to the United States for the Thanksgiving holidays before returning in December for two weeks of intensive talks.

Today he repeated his belief that a deal was "doable" by the end of that fortnight.

"Nothing we have seen or heard here during the course of this week changes that assessment," he said.

The ex-White House envoy acknowledged that he was ambitious in his objectives, but added: "I believe we are aiming high but we are aiming well within the range of what can, and I would say should, be accomplished."

Dr Haass and Dr O'Sullivan chaired a plenary session with all the party delegates involved in the process this afternoon.

He said the exchanges were "serious, thoughtful and creative" and praised the "open mindedness" of those involved.

Dr O'Sullivan said a "positive dynamic" had developed.

"The dynamic is one we would like to preserve and strengthen," she added.

The chair and deputy chair have held more than 100 meetings involving around 500 individuals and received about 600 submissions to an online consultation in their work to date.

Dr Haass said the latest trip had been successful in gaining an understanding of the parties' positions and areas of potential agreement and disagreement. He said the process would progress to the next level in December.

The Haass talks have been billed as the most important since the 2010 Hillsborough Castle negotiations when responsibilities for policing and justice were devolved to Stormont from Westminster.

They follow one of the most difficult years in Northern Ireland since the signing of the Good Friday Agreement.

Loyalist resentment over flags and parading issues sparked mass protests, some of which boiled over into violence on the streets, while republicans have been heavily criticised by victims' campaigners for holding a number of IRA commemorations.

There are worries that tensions could ramp up again next week as loyalists angry at last December's decision by Belfast City Council to limit the number of days the Union flag flies on City Hall are proposing fresh demonstrations to mark the first anniversary of the contentious vote.

The talks come at a time when relations within the Executive are also under strain, particularly between the Democratic Unionists and Sinn Féin.