David Cameron has warned there are a "lot of difficulties" at Stormont but insisted he has no sense of a power-sharing crisis.
And the Prime Minister also side-stepped any suggestion he may have to intervene to prevent the negotiations on flags, parading and the past – being chaired by American diplomat Richard Haass – from collapsing.
On the eve of the Conservative Party's annual conference in Manchester, Mr Cameron said he believes First Minister Peter Robinson and Deputy First Minister Martin McGuinness "work hard" at their relationship.
And he rejected criticism from shadow Northern Ireland secretary Vernon Coaker at this week's Labour Party gathering in Brighton that the coalition government's approach to Northern Ireland appears "semi-detached".
"I don't accept that for a moment. I mean, after all, I am the prime minister that brought the G8 to Northern Ireland. I think Northern Ireland is an absolutely vital part of our United Kingdom," Mr Cameron said.
"I brought together Martin McGuinness, Peter Robinson and the Secretary of State (Theresa Villiers) here in Downing Street to sign a new accord for economic development in Northern Ireland so we can really get shared future going."
His comments came amid fears that Sinn Fein could reciprocate the DUP's withdrawal of support for the Peace and Conflict Resolution Centre at the Maze by stalling other parts of the Executive's programme for Government.
Relations between the controlling parties at Stormont, the DUP and Sinn Fein, have been deteriorating over recent months in a barrage of controversies including the Union flag protests, parading and the republican commemoration of two former IRA volunteers in Castlederg.
Then this week the row deepened after Sinn Fein President Gerry Adams signalled the London and Dublin governments may have to become involved in "the problem" over the peace centre.
Mr Adams' speech in the Dail in Dublin was followed by former SF Junior Minister Gerry Kelly insisting there is "crisis" in the power-sharing administration – and the DUP counter-attack that the real issue was a "management" crisis within Sinn Fein.
STORY SO FAR
Tensions between the two top Stormont parties heightened this week after a former Sinn Fein minister warned power-sharing is "in crisis". Neither the DUP nor Sinn Fein are threatening to collapse the Assembly but there are fears worsening relations could endanger the prospects for the Haass talks on parading, flags and dealing with the past.