Update - 12.30pm: Gerry Adams has said his use of the n-word in his tweet last night was "inappropriate".
Speaking today at Connolly House in Belfast, Mr Adams said: "Django Unchained is a powerful film which highlights the injustices suffered by African Americans through its main character Django.
"In my tweets I described him as a ‘Ballymurphy n……‘ and ‘an uppity Fenian.’
"I have acknowledged that the use of the n-word was inappropriate. That is why I deleted the tweet. I apologise for any offence caused.
"I stand over the context and main point of my tweet about the Django which were the parallels between people in struggle.
The Sinn Féin President said that, like African Americans, Irish nationalists were denied basic rights.
He said: "The penal laws, Cromwell’s regime, and partition are evidence of that.
"In our own time, like African Americans nationalists in the north, including those from Ballymurphy and west Belfast, were denied the right to vote; the right to work; the right to a home; and were subject to draconian laws.
While there are parallels between people in struggle, the tweet was inappropriate" - Gerry Adams https://t.co/0kEyhj9FZd— Gerry Adams (@GerryAdamsSF) May 2, 2016
"This changed because we stood up for ourselves. We need to continue to do that.
"The civil rights movement here, of which I was a founding member, was inspired and based its approach on the civil rights campaign in the USA.
"I have long been inspired by Harriet Tubman; Frederick Douglass; Rosa Parks; Martin Luther King and Malcolm X who stood up for themselves and for justice."
Update - 12pm: Sinn Féin President Gerry Adams has told reporters he is sorry for using the N-word in a tweet last night.
Mr Adams said: "I stand over the context and the substance of the point I was making which is the parallel between the plight of people here in Ireland and the struggle of people of African-American extraction."
Earlier: The Sinn Féin President has come under fire for a tweet he wrote using the N-word.
Gerry Adams sent the tweet last night, after apparently watching 'Django Unchained', a film set in pre-civil war era America.
Mr Adams has since deleted the tweet, but he has been accused of being racist as a result of it.
In a statement he said anyone who is offended by the use of the N-word misunderstood the context in which it was used.
Any1 who saw Django would know my tweets&N-word were ironic.Nationalists in Nth were treated like African Americans.— Gerry Adams (@GerryAdamsSF) May 2, 2016
The Sinn Féin President said: "My tweets about the film Django have triggered a lot of interest. Anyone who has seen the film, as I did last evening, and who is familiar with the plight of nationalists in the North until recently, would know that my tweets about the film and the use of the N-word were ironic and not intended to cause any offence whatsoever.
"Attempts to suggest that I am a racist are without credibility. I am opposed to racism and have been all my life.
"The fact is that nationalists in the north, including those from Ballymurphy, were treated in much the same way as African Americans until we stood up for ourselves.
"If anyone is genuinely offended by my use of the N-word they misunderstand or misrepresent the context in which it was used. For this reason I deleted the tweets."