Sinn Fein President Mary Lou McDonald has apologised for the IRA's murder of Lord Mountbatten in Sligo in 1979.
Mrs McDonald was speaking following the funeral of Prince Philip, Lord Mountbatten's nephew on Saturday, after his death last week at the age of 99.
She told Times Radio she was sorry that Mountbatten (79) was killed when the fishing boat he was on was blown up by the IRA.
The Sinn Fein leader was asked whether she would be willing to apologise to Prince Charles, who had a particularly close relationship with the earl.
"The army and armed forces associated with Prince Charles carried out many, many violent actions on our island," Mrs McDonald said.
"I can say of course I am sorry that happened. Of course, that is heartbreaking. My job, and I think that Prince Charles and others would absolutely appreciate this, my job is to lead from the front, now, in these times."
The Sinn Fein leader said she wanted to ensure no other family lost a loved one to conflict.
“I believe it is all our jobs to ensure that no other child, no other family, no matter who they are, suffers the same trauma and heartbreak that was all too common on all sides of this island and beyond," she said.
“I have an absolute responsibility to make sure that no family faces that again and I am happy to reiterate that on the weekend that your Queen buried her beloved husband."
Lord Mountbatten was holidaying at Classiebawn Castle, Mullaghmore on August 27 1979 when he was murdered by the IRA.
A bomb exploded on a Shadow V boat he was fishing on, while he was pulled alive from the water by nearby fishermen, he died from his injuries before being brought to shore.
Also killed were Lady Doreen Brabourne, the 83-year-old mother-in-law of the earl's daughter, his 14-year-old grandson Nicholas Knatchbull and Fermanagh schoolboy Paul Maxwell, who was working as a boat boy while on holiday with his parents.
Mrs McDonald's predecessor as Sinn Fein President, Gerry Adams had previously declined to apologise for Lord Mountbatten's death.
He made the comments after shaking hands with Prince Charles during a historic meeting at the National University of Ireland, Galway in 2015.
“He and his family were hurt and suffered great loss by the actions of Irish republicans. I am very conscious of this and of the sad loss of the Maxwell family, whose son Paul was killed at Mullaghmore, and I thank all involved, including Charles, for their forbearance,” Mr Adams said.
When asked about previous comments that Lord Mountbatten "knew the danger" in coming to Ireland the then-Sinn Fein leader said: “I stand over what I said then. I'm not one of those people that engages in revisionism. Thankfully the war is over.”
Last year a letter from Prince Philip emerged in which he expressed his hope the reaction to the murder of his uncle would lead the IRA to turn away from violence.
"Let us hope that the great wave of revulsion against this senseless act of terrorism may yet help to bring a change of heart in those who believe that violence and brutality are the only solutions to their problems," he wrote.
The letter came to light as part of the collection of the late actor Lionel Jeffries, who wrote to a number of senior royals following the murder of Lord Mountbatten to express his sympathy.