The First Minister is to meet the Director of Public Prosecutions (DPP) over his decision to stop the prosecution of Jonesborough man Seamus Daly, 45, who was accused of the Omagh bombing.
Arlene Foster said the way in which the families of those who died were treated is unacceptable.
“It is very disappointing to hear of the manner in which the families learned about this development yesterday,” she said.
“We will want to ask questions around that.
“We will also want to ask questions about why the DPP decided not to proceed in terms of this case and we’ll be following that up with him.
“There’s always hope in terms of finding justice.”
A spokeswoman for Director of Public Prosecutions Barra McGrory said he had offered to meet the families and was arranging to meet Mrs Foster.
“The director has reiterated his disappointment that the prosecution had to be withdrawn in this case,” she said.