The three groups made a joint statement in which they publicly declared their intention to turn away from the organised crime they shifted into following the 1998 Good Friday Agreement peace deal.

"We fully support the rule of law in all areas of life and emphatically condemn all forms of criminal activity," the Red Hand Commando, Ulster Defence Association and Ulster Volunteer Force groups said at a press conference in Belfast.

Loyalists are the working-class hardcore of Northern Ireland's Protestant British community. Their loyalty is to the British crown and keeping Northern Ireland within the United Kingdom.

Loyalist paramilitaries have been on ceasefire since 1994 and officially stopped their armed campaigns in 2007.

The 1998 Good Friday peace accords largely ended three decades of inter-community bloodshed in Northern Ireland, known as the Troubles.

Since then, paramilitary groups have drifted into organised crime, including drug trafficking, money laundering and extortion.

"Individuals who use criminality to serve their own interests at the expense of loyalist communities are an affront to the true principles of loyalism," the groups said in a statement.

"We cannot allow criminals to hinder transformation and the ground in which such people stand is now shrinking."

In their first joint statement since the 1994 ceasefire, the groups said any members involved in criminality would be expelled.

The agreement came after lengthy discussions with three Protestant church leaders. Churchmen in Northern Ireland have historically played an "honest broker" role in the peace process.

- 'Advocates for change' -

The loyalist paramilitary groups said they would no longer be "apologists for conflict" but "advocates for change".

"Loyalists must have ownership and control of their own future," the statement said.

Their declaration was welcomed by Ireland's prime minister, Leo Varadkar, who said it was in keeping with the 1998 peace accord.

"The Irish government is committed to protecting the gains of the peace process in Northern Ireland and across these islands, and we particularly welcome this commitment to ensure loyalist communities are at the centre of Northern Ireland's peace and political transformation," he said in a statement.

Loyalist paramilitaries are held responsible for around 1,000 of the around 3,500 deaths during the Troubles. Nearly 900 were civilians.

The 1998 peace accords set up the devolved Northern Ireland Assembly, with a power-sharing executive running affairs in the province.

However, power-sharing collapsed in January 2017 amid a breakdown in trust and the province has been in political limbo ever since.

Despite several efforts, the main parties from the British Protestant and Irish Catholic communities are still quibbling and unable to form an executive.