The new US special envoy to Ireland arrives in Belfast on Monday for his first series of meetings with the parties.
Dr Mitchell Reiss took over the role from Mr Richard Haass last month, having also been appointed to Mr Haass's former position as director of policy planning at the US State Department.
Dr Reiss is to begin a series of getting-to-know-you meetings in Belfast on the eve of Tuesday's opening plenary session of the Belfast Agreement review, to be chaired by the British and Irish governments.
He has extensive experience of disarmament issues and relations with North Korea.
He has also worked as head of schools of government and international relations at American universities.
He held positions on the National Security Council at the White House, at the State Department and in the Congressional Research Service.
Like his predecessor, he is an author, having written Bridled Ambition: Why Countries Constrain Their Nuclear Capabilities and Without the Bomb: The Politics of Nuclear Non-Proliferation.
He has also contributed to nine other volumes and written more than 50 articles on international security and arms control issues.
A US government source insisted Dr Reiss would be in "listening mode" on his first visit.
He is expected to address decommissioning and the current attempts to restart the political process at Stormont.
Dr Reiss may also observe the opening session of the review which begins at Parliament Buildings on Tuesday.
The review is expected to last until Easter at the earliest and will meet on most Mondays and Tuesdays.
Mr Haass left the State Department last summer and has taken up a position with an independent policy think-tank in his native New York.
The Sinn Féin president, Mr Gerry Adams, was the first party leader to meet Dr Reiss when he was in the US last week.