The new United States envoy to Northern Ireland has been named as Mitchell B Reiss. Mr Reiss replaces Richard Haass and will take up the post early in the New Year.

He was described as a US government official with extensive experience on nuclear disarmament.

Mr Reiss has spent time working with the North Korean government on nuclear disarmament, and will focus on the issues of IRA decommissioning and attempts to restore the power-sharing administration at Stormont.

Welcoming the appointment, SDLP leader Mark Durkan said the appointment showed that the US remained committed to building peace in Ireland and he looked forward to meeting Mr Reiss as soon as possible. Mr Durkan said Richard Haass had played an enormously helpful role in the process.

Sinn Féin's Chief Negotiator Martin McGuinness MP also welcomed the announcement. He said it was a signal of the ongoing commitment of the US Administration to the Irish peace Process.

'Ambassador Haass did play a positive role during his term and I wish him well in the future,' he said. Mr McGuinness congratulated Mr Reiss on his appointment and said the Sinn Féin President, Gerry Adams, had already written to him and the party looked forward to meeting Mr Reiss at the earliest opportunity.