RIO DE JANEIRO -- Brazilian President Dilma Rousseff on Thursday mourned former South African leader and Nobel Peace Prize winner Nelson Mandela, who died earlier in the day at the age of 95.

In an official statement, the president expressed her condolences to Mandela's family and all South Africans, saying Brazil treasures the memory of the great leader, who helped abolish South Africa's apartheid system.

Mandela's example "will guide all those who fight for social justice and for peace in the world," said Rousseff.

One of the most significant figures of the 20th century, Mandela "conducted with passion and intelligence one of the most important processes of liberation in contemporary history, the end of apartheid in South Africa," she added.

"His fight became a paradigm not only for the African continent but also for all those who fight for justice, freedom and equality," she said.

Mandela served 27 years in prison for his opposition to the segregationist regime in South Africa, and then went on to become the nation's president.

After the end of apartheid, Mandela was awarded the Nobel Peace Prize in 1993. In the following year, he was elected president of South Africa, the first black man to take the post.