Gerry Adams has repeated his denial that he was a member of the IRA, but said he will never disassociate himself from the organisation.
The former Sinn Féin president was giving evidence to a fresh inquest into the killing of 10 people in the Ballymurphy area of Belfast in 1971.
The episode dubbed the "Ballymurphy massacre" started on 9 August as the British Army moved into republican strongholds to arrest IRA suspects after the introduction by the Stormont administration of the controversial policy of internment without trial.
A new inquest at Belfast Coroner's Court is examining the deaths of 10 civilians, including a Catholic priest and a mother of eight, between 9 and 11 August.
Claims that IRA gunmen were in the area at the time have been disputed during the inquest hearings.
David Heraghty, counsel for coroner Siobhan Keegan, put to the Louth TD that he was a senior member of the IRA in the area at the time.
Mr Adams responded: "I was not a member of the IRA, I have never disassociated myself from the IRA and I never will until the day I die.
"I understand that victims of the IRA won't like what I am saying... I deeply regret there was a war."
He praised the "maturity of the IRA" for "embracing the peace process" and "fading" away.
A barrister for the Ministry of Defence put to Mr Adams that he was commander of the IRA in the Ballymurphy area in November 1969.
Mr Adams responded: "That's not correct. I gave a full answer to this question when it was put to me by Mr Heraghty."
Earlier in the hearing, Mr Adams detailed how, during the mid to late 1960s, he was involved with republicanism, describing himself as an "organiser" and a member of Sinn Féin.
The Provisional IRA is believed to have been founded in 1969, and went on to become the dominant force in violent Irish republicanism until the Good Friday Agreement in 1998.
Mr Adams told the inquest that in 1969 he was in the minority as not having been involved with the military wing of republicanism.
"I had the distinction of having been active since the mid 1960s and having been involved in the type of agitated activity. I continued with that," he told the inquest.
"The military tendency within republicanism was the dominant tendency."
He described Ballymurphy in 1971 as being under a "heavy" and "aggressive occupation" by the British Army and claimed CS gas and rubber bullets were frequently deployed against residents.
"The British government opted for the military option and reneged on its political responsibilities, and handed it over to the generals," he told the inquest.
Mr Adams said he did not witness any of the deaths despite his home being in Divismore Park.
He said at that time he rarely slept at his family home following an incident when masked men called at the front and side doors looking for him, when he was staying with a friend in nearby Springhill Crescent.
Mr Adams said his father and brother Liam were interned on 9 August , and soldiers had asked for him.
Asked whether the IRA had attacked the Army on 9 August , Mr Adams told the inquest he did not have direct knowledge of the Provisional IRA's actions, but he understood it ordered no engagement with the British Army that day.
He said there had been a rumour in the area that a gunman from the Official IRA had fired on the Henry Taggart Memorial Hall where the Army was based, but added that the "bush telegraph" in those days was "sometimes accurate and sometimes inaccurate".
He said it had been a "sensible decision" by the Provisional IRA not to "engage the British Army", for the "safety of the community and safety of the volunteers".
The inquest continues.
- UTV Correspondent Jane Loughrey was in court: