Sinn Féin president Gerry Adams has acknowledged he "made a mistake" in using the N-word in a tweet in which he compared the struggle against slavery in the US to the plight of Irish nationalists.

Mr Adams initially defended using the racist term in a tweet about Quentin Tarantino film Django Unchained but later said its use had been "inappropriate".

“When one makes a mistake the best you can do is own up to it,” he told RTÉ Radio One on Monday.

The Louth TD faced strong criticism on Social media on Sunday night and into Monday after he posted the tweet to his 110,000 followers using the word.

Mr Adams appeared to draw comparisons between of one of film's characters, a slave, and the treatment of nationalists in Ballymurphy in west Belfast.

In 1971 eleven people were killed in the Ballymurphy area by British soldiers.

“Watching Django Unchained - A Ballymurphy N****r!” Mr Adams tweeted.

A second message read “Django - an uppity Fenian!”

The online posts, which have since been deleted, were picked up by the international press, including the Washington Times.

Mr Adams first insisted his use of the N-word was ironic and it was not his intention to cause offence.

In a statement from Mr Adams, issued by the Sinn Féin press office early on Monday, he said he has been opposed to racism all his life.

“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.”

However, in a second statement on Monday afternoon, Mr Adams said while “there are parallels between people in struggle, the tweet was inappropriate” and he apologised for any offence caused.

“I stand over the context and main point of my tweet about Django which were the parallels between people in struggle,” Mr Adams statement continued.

“Like African Americans, Irish nationalists were denied basic rights. 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.”

“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 Douglas; Rosa Parks; Martin Luther King and Malcolm X who stood up for themselves and for justice.”

The focus on Mr Adams’ comments are unhelpful for Sinn Féin days before the Assembly elections on May 5th.

Belfast writer Tim Brannigan, a former republican prisoner who is of mixed race and know Mr Adams, said he was shocked the Sinn Féin leader had used the racist slur in a tweet.

“It was a mixture of shock, disbelief and disappointment,” the west Belfast man said.“I didn’t expect someone with his background and politics to use that sort of language.

“I certainly believe the word is offensive and I was surprised he used it,” said Mr Brannigan. “His equation of nationalists with slaves is disproportionate.

“The word itself is obviously racist and offensive but using it once in an off the cuff way does not make anyone a racist in the way right wing neo nazis groups are.

“We can all make ill judged remarks. I think Gerry had done that but I would not call him a racist.The facts would suggest the north is way behind the curve on racial and equality issues that senior politicians don’t even know what language is appropriate.”