The Taoiseach Leo Varadkar says the protection of directors of Quinn Industrial Holdings (QIH) is a top priority for the Government.
Me Varadkar met personally with the five directors on Sunday.
His visit follows what he described as the "barbaric abduction" of Kevin Lunney and joint investigations by Gardaí and the PSNI.
Mr Varadkar says he sought the meeting in order to thank the directors for "their courage, their determination and their commitment to this vitally important company which creates so much employment and economic activity in a region that needs it."
He says he wanted to hear their views and to assure them of the Government's support for QIH, which employs more than 800 people in Ireland and Northern Ireland.
"In particular, I wanted to thank Kevin Lunney for the resilience he has shown following his barbaric abduction, assault and torture.
"I discussed my recent meeting with the Garda Commissioner and the Minister for Justice.
"I assured them that their own security, that of their employees, and law and order in the border region is treated with the utmost seriousness at the top of Government.
"Law and order must, and will, prevail in all parts of the country.
"We agreed to stay in contact as the criminal investigation against the perpetrators proceeds."
Justice Minister Charlie Flanagan says he has "every confidence" in An Garda Síochána and the PSNI.
He says: "Policing in the border region has long been very challenging as criminals have always sought to exploit that border.
"I have every confidence that An Garda Síochána and the PSNI are working together at historically close levels to prevent and investigate cross-border crime and the fruits of that cooperation were evident this week in a series of major searches.
"Nobody is above the law anywhere on the island and the new Joint Investigation Team agreement signed this week formalises the necessary policing cooperation and leaves no hiding place for criminals operating in the border area - they will be relentlessly pursued in both jurisdictions."
Minister Flanagan adds that the team will further support the existing Joint Agency Task Force, established under the Fresh Start Agreement.
There are already 1,500 Gardaí in the border region - including three Garda Armed Support Units - with 150 additional officers assigned there in the last two years.
Following the meeting with Mr Varadkar, QIH said it "welcomes the personal interest taken by An Taoiseach in bringing to justice those responsible for a campaign of terror and intimidation against its staff.
"The company believes the establishment of a joint investigative team is a critical step and is satisfied that the necessary resources and resolve are now in place for an effective investigation."