Washington  - The woman president-elect Barack Obama calls "granny" will travel to his inauguration from her home in Kenya.

Sarah Obama, the widow of Barack Obama's paternal grandfather, shares no blood with the president-elect but is his step-grandmother. He met her on the trip to Kenya that he details in his memoir Dreams From My Father.

She is to join African ambassadors to the US, Kenya's Foreign Affairs Minister Moses Wetang'ula and African Union officials at an unofficial inaugural ball, the organizers said Tuesday. The Corporate Council on Africa, the Kenyan Embassy, the African Union are among the sponsors.

Obama is to be inaugurated on January 20 and the festivities will feature a slew of both official and unofficial parties. The inaugural committee said Tuesday that there would be 10 official balls that the new president will attend, including one designated specifically for young people and one known as the neighbourhood ball for Washington residents.

"We are hosting events to bring people from all walks of life and from across the country - from the president-elect and vice president-elects home states, as well as every corner of the nation - to celebrate this countrys unity moving forward," Presidential Inaugural Committee Executive Director Emmett Beliveau said in a statement.

Other official balls will include one for Obama's home states of Illinois and Hawaii, one for vice president-elect Joe Biden's home states of Delaware and Pennsylvania, a ball for military members and five regional balls. (dpa)