A unionist politician has urged the Republic's new government to "face up" to the country's role in the Troubles.
Ulster Unionist MLA Doug Beattie called for an "honest assessment" from the new administration.
He was speaking after it was announced that Fianna Fail, Fine Gael and the Green Party had formally agreed on a programme for government yesterday.
The coalition government came after months of negotiations between Micheal Martin, who will become the new Taoiseach until December 2022 on a rotational basis, Leo Varadkar and Eamon Ryan.
Mr Beattie, an Upper Bann MLA and the UUP's justice spokesman, referred to a pledge in the new coalition government's agreement to address the legacy of the Troubles by working with Westminster and Stormont.
He added that if there was to be a "serious examination" of the Troubles then the Republic must make an "honest assessment and acknowledgement" of the role it played.
Mr Beattie continued: "This will include the presence of IRA arms dumps and training camps on its territory; the network of safe houses; the hundreds of gun and bomb attacks the IRA was able to mount from the Republic against targets in Northern Ireland (and) the ethnic cleansing campaign against border Protestants; the burial of the bodies of the Disappeared in unmarked graves; collusion between rogue elements of the Garda and the IRA, as was proven in the Smithwick investigation into the murder of RUC officers Breen and Buchanan; the ease with which IRA terrorists were able to live freely in the Republic, and the overwhelming difficulties the UK repeatedly faced in trying to extradite terrorist suspects from the Republic.
"If the new Dublin government really wants to 'address the painful legacy of the Troubles' then it could start by delivering the meaningful cooperation long-promised to the families of the victims of the 1976 Kingsmill massacre, and demonstrating its bona fides.
"Actions really do speak louder than words."
The DUP stated that First Minister Arlene Foster called Mr Martin and congratulated him on his new role as Taoiseach.
"We want to have a positive relationship and deal with matters of mutual concern to our two jurisdictions," the party said.
Alliance Party MLA Andrew Muir said his party welcomed the formation of a new Irish Government as "certainty and stability" will prove helpful amidst the challenges the island is facing, both north and south.
"We look forward to working collaboratively on a north-south basis and further developing an all-island economy," he added.
The SDLP said the party had previously worked closely with Fianna Fail leader Mr Martin to influence the draft programme for government, which made important cross-border commitments.
"We look forward to a government being formed, to deliver for people across this island and continuing our strong working relationship," it added.
Sinn Fein, which received the most first preference votes in February's election and won 37 seats, did not respond when asked if it would like to comment on Mr Martin's appointment as Taoiseach.