Taoiseach Enda Kenny has urged anyone with information about those abducted, murdered and secretly buried during the Troubles to help end the decades-long suffering of their families.
Relatives of the victims, known as the Disappeared, met Mr Kenny and presented him with a copy of a recently published book setting out some of their stories.
Afterwards, in a statement, Mr Kenny said he expressed his sympathy to the families and supported their ongoing fight to have the remains of their loved ones located and returned for burial.
"I am glad to have the opportunity this evening to meet with and to hear the stories of those families whose loved ones were taken, killed and then hidden from them in such a callous and tragic way," he said.
"Information from the public is absolutely essential to help to bring an end to their pain."
Mr Kenny called on anyone with information about any of the cases to contact the Victims' Remains Commission in strict confidence.
"I also call on anyone who knows anyone else who may have relevant information to use their influence to encourage them to make it available to the commission," he said.
"This is a matter of common human decency. These families have suffered enough and somebody out there can help to bring an end to that suffering."
The Taoiseach also said in the statement that he met the Independent Commission for the Location of Victims' Remains (ICLVR) and was updated on their work.