DUBLIN, Ireland -- The Irish Republican Army said yesterday it offered to kill four people -- including two expelled IRA members -- for killing a Belfast man in its latest effort to defuse criticism over the case, which has cast a shadow over Northern Ireland's peace process.

The victim's family rejected the offer during a five-hour meeting with an IRA representative, the outlawed group said in a statement.

The IRA, which initially denied involvement in the Jan. 30 killing of Robert McCartney, a 33-year-old Catholic, has faced unrelenting criticism over the slaying, alleged intimidation of witnesses and destruction of evidence. Nobody has been charged, though the attack took place at a crowded pub and involved well-known local IRA figures.

The group said an internal inquiry determined that four people helped kill McCartney following a dispute at a pub. It called on all four, as well as all witnesses, to "give a full and honest account" -- but it didn't specify to whom.

The IRA and its Sinn Fein party reject the authority of police in the British province, which British, Irish and U.S. governments say is a major obstacle to justice in the case.

The IRA said it told the McCartney family "in clear terms that the IRA was prepared to shoot the people directly involved in the killing of Robert McCartney." But the group said the family instead "wanted those individuals to give a full account of their actions in court."

The IRA two weeks ago expelled three members who it said were responsible for the killing. Sinn Fein then suspended seven party members allegedly involved in the attack.

The U.S. envoy to Northern Ireland confirmed yesterday that McCartney's five sisters, who have waged a rare public campaign against IRA intimidation in their hard-line Catholic neighborhood of Belfast, have been invited to the White House on St. Patrick's Day.

"I don't know how anybody can help but be impressed by them," the envoy, Mitchell Reiss said. One of the slain man's sisters, Catherine McCartney, said she hoped President Bush could help.

"The case we'll put to Bush will be the same as it has been to everybody here in Ireland: that these men must be brought to justice, and he should use whatever influence he has to make that happen," she said.