Image copyright Charles McQuillan Image caption Irish Prime Minister Enda Kenny and Prime Minister David Cameron left Northern Ireland without securing a deal

Talks between Northern Ireland's political parties are to resume on Tuesday, it is understood.

On Friday, Prime Minister David Cameron and Irish Prime Minister Enda Kenny left Northern Ireland without securing a deal.

The outstanding issues include the budget, welfare reform and dealing with the legacy of the Troubles.

The DUP and Sinn Féin said no deadline had been set but a solution would require hard work from all parties.

"If we can't get agreement, particularly on the public finances, I think we have a real problem here," the DUP's Jeffrey Donaldson said.

"The first minister has made clear that it will be very difficult for the executive to limp on in those circumstances and to deliver good government for Northern Ireland.

"So, we're not contemplating failure, we really need to get agreement on these important issues."

Sinn Féin's Gerry Kelly said: "The deal that should have been done, should have been done in the last few days.

"Though I wish I could tell you I was hopeful, I can tell you that we will work hard to see if that will occur.

"But unless the British prime minister changes his attitude and that ideological doctrine of cuts no matter what, then I think we are in difficulty."

Following talks on Thursday evening and Friday morning, both the DUP and Sinn Féin said the financial package put forward by Mr Cameron was not adequate.

Mr Cameron said it would have given the executive "financial firepower" of up to £1bn.

However, the Northern Ireland parties said the package did not represent new money.