Nelson Mandela's health continues to decline as the former president of South Africa battles a lung infection.

"Former President Nelson Mandela's condition remains unchanged in hospital and doctors continue to do their best to ensure his recovery, well-being and comfort," the South African government said Tuesday night in a statement.

The iconic leader has been hospitalized since June 8 with a recurring lung infection, but it is only recently that he has reached critical condition. Mandela is no longer able to breathe unassisted and his family have been told to "prepare for the worst," The Sun reported Wednesday.

South Africans have come out in droves in support of Mandela, carrying signs and writing hopeful messages outside his hospital.

"We must support him and support his family," said South African President Jacob Zuma on Tuesday. "We must demonstrate our love and appreciation for his leadership during the struggle for liberation and in our first few years of freedom and democracy by living out his legacy and promoting unity, non-racialism, non-sexism and prosperity in our country,"

Mandela's ailing health has become known throughout the world and many leaders have voiced their prayers and concerns for him.

"We have seen the latest reports from the South African government that former president Mandela is in critical condition," said U.S. National Security Council spokeswoman Caitlin Hayden. "Our thoughts and prayers are with him, his family and the people of South Africa."

Mandela spent 27 years in prison after fighting for the end of racial segregation in South Africa. Often considered the leading force for South African democracy, Mandela was elected president of the country four years later. He became the first black president in the nation's history.

"We must all be planning what to do next month in marking our 67 minutes of doing good for humanity as called upon by Madiba [Mandela's clan] to do so, when he launched the International Mandela Day campaign," President Zuma said Tuesday. "Let us make it the biggest Mandela Day ever on the 18th of July, focusing on doing good all over the country."

The 94-year-old activist will turn 95 on July 18.

Watch a biography of Mandela's life here:

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