Clinton and Mandela, August 6, 2012
Clinton meets with Nelson Mandela, 94, former president of South Africa, at his home in Qunu, South Africa, August 6, 2012. Clinton praised the "beautiful" smile of her friend Mandela when they met at his country home on Monday during her multi-nation trade and security tour through Africa. Mandela, in failing health, has only seen a few visitors outside his family in recent years. During his 94th birthday celebration last month, the anti-apartheid leader met Hillary's husband and former U.S. President Bill Clinton. Reuters/Jacquelyn Martin/Pool

Hillary Clinton has been a woman of few tweets since launching her Twitter account in June.

But the former secretary of state made a return Tuesday to offer well wishes to former South African President Nelson Mandela, who is in a hospital and may be near death.

Clinton referred to 94-year-old Mandela by his clan name, Madiba.

Nelson Mandela -- who was imprisoned for 27 years in South Africa when he challenged white minority rule and became the first democratically elected president in 1994 -- remains in critical condition.

Read More: Nelson Mandela In Critical Condition

“The doctors are doing everything possible to get his condition to improve and are ensuring that Madiba is well-looked after and is comfortable. He is in good hands,” South Africa’s President Jacob Zuma said in a statement.

One media report said Mandela suffered a heart attack, but Zuma knocked down this rumor, saying there was "no truth at all in that report."