Muhammad Ali death update

Ali died last Friday at the age of 74 in hospital in Phoenix, Arizona.

World leaders will be among thousands attending Friday's procession and memorial service in Louisville, Kentucky, where Ali was born.

The White House said Mr Obama and his wife Michelle will be at daughter Malia's high school graduation.

They will send a letter to the Ali family with White House senior adviser Valerie Jarrett, who knew Ali.

Bob Gunnell, a spokesman for the Ali family, said Mr Obama and Ali's widow Lonnie had spoken by telephone.

"This began with 'The Champ' a decade ago," spokesman Bob Gunnell told reporters at a news conference. "As he convened the meeting, he said, 'This is what I would like to see, this is the type of program that I would like to see, that is inclusive of everyone, where we give as many people an opportunity that want to pay their respects to me.' "

Ali also said it was important that the memorials be conducted in the Muslim tradition, Gunnell said.

Organisers say Ali helped plan his own funeral as a "last statement" to the world.

The charismatic Ali, a dazzling fighter and outspoken civil rights activist who became one of the 20th century's towering figures, died on Saturday (AEST) at age 74 after health problems complicated by a long battle with Parkinson's disease.

Thousands of people are expected to join the funeral in his hometown of Louisville, Kentucky.

Former US President Bill Clinton and actor Billy Crystal are also set to speak.

Ali died last Friday at the age of 74 in hospital in Phoenix, Arizona.

A spokesman said his death was from "septic shock due to unspecified natural causes".

The the three-time world heavyweight champion had been suffering from a respiratory illness, a condition that was complicated by Parkinson's disease.

A public memorial is scheduled for Friday at 2 p.m. ET at the Yum Center, a basketball arena in the city where Ali grew up and began his amateur career as a 12-year-old. Information on tickets will be released later. The Yum Center has just more than 22,000 seats.

The service will be streamed live on the website for the Muhammad Ali Center.

The three-time world heavyweight champion - one of the world's greatest sporting figures - died on Friday night at a hospital in Phoenix, Arizona.

The 74-year-old had been suffering from a respiratory illness, a condition that was complicated by Parkinson's disease.

A public funeral will be held for the boxer on Friday in his hometown of Louisville in Kentucky.

"He was a citizen of the world and would want people from all walks of life to be able to attend his funeral," said the family spokesman, Bob Gunnell.