Gary Hart, the US Envoy to Northern Ireland, met in Belfast yesterday with Northern Ireland Secretary Teresa Villiers, and party leaders at Stormont, the seat of the Northern Irish government.
The aim of his visit is to explore "how the United States can best support constructive engagement in the current negotiations and work with all parties to foster an enduring peace in Northern Ireland."
Sinn Féin MLA Martin McGuinness said that the US has a key role to play in helping to achieve a resolution to the ongoing difficulties facing the political process.
Speaking after his meeting with Hart, McGuinness said:
"I held a positive discussion with Senator Hart today as part of the ongoing engagement of the US administration with the political process.
"Throughout the peace process, successive US administrations have played key roles in helping bring our society forward.
"They have done so without fear or favor, they have been supportive of all parties and you only have to think of the huge contribution made by people like George Mitchell to realize what a friend the US has been to our peace process.
"I'm delighted that Gary Hart is involved once again and I think all parties should support him being afforded a significant role in the current talks as a recognition of the important influence and support which the US can bring to the table."
Hart, a former senator from Colorado, was appointed envoy in October 2014.
Today he travels to Dublin to discuss the Northern Irish political crisis with Taoiseach (Prime Minister) Enda Kenny and Minister for Foreign Affairs Charlie Flanagan.