An independent assessment of paramilitaries in Northern Ireland has been commissioned by the Government.

The three person panel, appointed by Northern Ireland Secretary Theresa Villiers, will examine findings from the security agencies such as MI5 and police on the structure, role and purpose of proscribed organisations.

It will report back next month.

The announcement follows the murder of a man by Provisional IRA members which has rocked the power-sharing political establishment at Stormont and was made as police officers investigating violent dissident republican activity discovered Semtex explosive, bomb detonators and almost 200 rounds of ammunition in West Belfast.

Ms Villiers said: "I am announcing today that the Government has commissioned a factual assessment from the UK security agencies and the PSNI (Police Service of Northern Ireland) on the structure, role and purpose of paramilitary organisations in Northern Ireland.

"This assessment will be independently reviewed and checked by three individuals who I will appoint. Their names will be announced early next week.

"This assessment will be published by mid-October and will be available to inform the parties' discussions and conclusions in the cross-party talks."

The mandatory coalition Executive in Belfast is teetering on the verge of collapse, with all but one of its unionist ministers having walked out over the shooting of former IRA member Kevin McGuigan by current members of the Provisionals.

Ms Villiers said she intended to establish dedicated funding to increase the capability of agencies working to tackle criminality and organised crime associated with paramilitary groups in Northern Ireland.

She said: "It will support agencies to enhance specialist capabilities such as forensic accounting to strengthen their capacity to seize criminal assets."

Talks with the administrations in Belfast and Dublin on how best to tackle cross-border crime such as fuel laundering and smuggling will also be established.

Cross-party discussions to resolve a crisis sparked by the murder of Mr McGuigan were due to begin on Monday but unionists had demanded UK Government action on paramilitaries before they begin.

Democratic Unionist Party (DUP) leader Peter Robinson, who has temporarily stepped aside as First Minister, said he was "content" key issues around paramilitary criminality were being addressed and said the DUP would be at the negotiating table next week.

He said: "We will be participating in the talks on Monday.

"I am not in the business of wrecking devolution. I want to see good, effective government in Northern Ireland. Whilst others may be focused on process, this party is focused on the right outcome."

Police said current members of the IRA were involved in shooting the 53-year-old father of nine last month, in a suspected revenge attack for the murder of former IRA commander Gerard "Jock" Davison in Belfast three months earlier.

That assessment has shone the spotlight on Sinn Fein and exerted pressure on the republican party to explain why security chiefs assess that the supposedly defunct paramilitary organisation is still in existence.

Mr Robinson added: "We need to know exactly whether they are collecting intelligence, whether there is any weaponry being brought in, whether there is a recruiting going on (and) what activities are they involved in."

Stormont Deputy First Minister Martin McGuinness said he was "pleased" unionist leaders would be present at next week's talks.

Politicians have a "burning duty" to find a resolution, he said.

"We will work with other parties to tackle the issue of armed groups, which want to drag us back to the past including active unionist paramilitaries and armed republican dissidents and organised criminals who are a blight on the community."

Mike Nesbitt, leader of the Ulster Unionist Party (UUP), which walked out of talks last week because the IRA was not top of the agenda, described Ms Villiers' statement as a "positive step forward".

He said he would speak to his party executive and "reflect where we go from here".

According to the Irish Government, the security assessment would be a one-off and would not pre-empt a decision on whether to revive a more long-term monitoring body similar.

Foreign Affairs Minister Charlie Flanagan said: "The Irish Government remains determined that organised crime from whatever quarter and in whatever manifestation continues to be tackled head on.

"There is already in place a high level of co-operation to deal with the cross-border aspects of such crime.

"We are committed to working in partnership to robustly tackle the activities of organised criminals who inflict such damage on our communities."

Mr Flanagan, who had talks with the Secretary of State ahead of the announcement, warned that time is running out for critical issues at Stormont to be resolved and he urged parties to get into talks.

He added: "After 10 days of shadow-boxing, it is essential that all of the five main parties in Northern Ireland, with the support of the two governments, urgently get down to the serious business of fully implementing the Stormont House Agreement and addressing the impact and legacy of continuing paramilitary activity."

PSNI Chief Constable George Hamilton also welcomed the new security assessment and pledged to work with partner agencies including An Garda Siochana to tackle organised crime.

"We welcome the independently reviewed assessment of paramilitary organisations announced by the Secretary of State and PSNI will play our part in assisting in this process," he said.

The Ulster Unionist Party's ruling executive unanimously endorsed Mr Nesbitt's recommendation to enter talks on Monday.