The Sri Lankan government on Monday declared a two-day mourning period in respect of anti-apartheid hero Nelson Mandela, ahead of Sri Lanka president attending the funeral as the Commonwealth Chair.

The Government Information Department under the Media Ministry announced that Tuesday and Wednesday would be days of national mourning during which the national flag will be flown at half-mast.

Sri Lanka President Mahinda Rajapaksa will fly to South Africa later this week to attend the funeral of former South African President Nelson Mandela, Presidential spokesman Mohan Samaranayake told media.

Rajapaksa will represent the 53 member Commonwealth as its chairman.

"Following his attendance at the funeral Rajapaksa will fly to Kenya on an official visit," Samaranayake added.

South Africa is preparing for the arrival of scores of world leaders as the official mourning continues for Nelson Mandela, international media reported.

Some 60 heads of state have confirmed their attendance at this week's memorial events, including US President Barack Obama, British Prime Minister David Cameron and Prince Charles.

The leaders of France, Australia, Germany, Canada, Spain, Brazil and a host of other nations will also fly into the country.

Celebrities, including Bono, Oprah Winfrey and Richard Branson are also expected to head to South Africa to pay their personal tributes to the man they considered a friend.