Namibia's President Hage Geingob has died at the age of 82 while receiving medical treatment at a hospital in the capital, Windhoek.

A veteran of the country's independence struggle, Geingob had been diagnosed with cancer and revealed the details to the public last month, The BBC reported. 

He died early on Sunday with his wife and children by his side, Vice-President Nangolo Mbumba announced.

Namibia "has lost... a distinguished servant of the people", he said.

According to the constitution, Mbumba will now act as president as there was less than a year left of Geingob's second term in office. Presidential and parliamentary elections had already been scheduled for November.

The exact cause of the president's death was not given but last month he underwent "a two-day novel treatment for cancerous cells" in the U.S. before flying back home on 31 January, his office had said.

Leaders from around the world have been sending condolence messages.

Among them is Cyril Ramaphosa, president of neighboring South Africa, who described him as "a towering veteran of Namibia's liberation from colonialism and apartheid".