WASHINGTON - WHITE House hopeful Barack Obama spoke on Thursday about the heart-wrenching mistake he made in not rushing to his mother's side before she died, and how he won't make the same mistake again with his grandmother.

In an unprecedented move 12 days before election day, the Democrat left the campaign trail on Thursday to be at the bedside of his ailing grandmother in Hawaii, who he described in his convention speech in August as one of his 'heroes'. When Mr Obama's Kansas-born mother, Ms Ann Dunham, passed away, I 'got there too late,' he told CBS television.

'We knew that she wasn't doing well but, you know, the diagnosis was such where we thought we had a little more time and we didn't. And so I want to make sure that I don't - I don't make the same mistake twice,' Mr Obama said.

Mr Obama told ABC television, in his last interview before flying to the Pacific state, that his grandmother Madelyn Dunham, 85, has been 'inundated with phone calls and emails and flowers from total strangers'. In his autobiographies Dreams of my Father and Audacity of Hope, Mr Obama wrote how his grandmother was instrumental in his upbringing.

In the ABC interview, to be aired on the Good Morning America programme on Friday, Mr Obama said the flood of support meant perhaps that his grandmother 'is getting a sense of, of long-deserved recognition towards the end of her life'.

When he accepted the Democratic nomination before 84,000 supporters in a Denver stadium in August, Mr Obama told how his grandmother 'worked her way up from the secretarial pool to middle-management, despite years of being passed over for promotions because she was a woman'.

'She's the one who taught me about hard work,' he said. 'She's the one who put off buying a new car or a new dress for herself so that I could have a better life. She poured everything she had into me.' 'Tonight is her night as well,' he said to rapturous applause.

Ms Dunham, who went by the nickname 'Toot' - a shortened form of the Hawaiian word for grandmother - was like a mother to him, the Democrat said.

He told CBS that his mother raised him 'with the help of my grandparents.

And so my grandmother, my grandfather and my mom, they're really the people who took care of me all throughout my childhood.'

'My grandmother's the last one left. She has really been the rock of the family, the foundation of the family. Whatever strength, discipline that I have, it comes from her.'

Asked if there could be political risk in taking time away from the campaign trail so close to the November 4 vote, Mr Obama said: 'I think most people understand that if you're not caring for your family, then you're probably not the kind of person who's going to be caring for other people.'

The Obama campaign has declined to specify the nature of the Ms Dunham's illness, apart from saying it was quite serious.