JOHANNESBURG — Nelson Mandela’s condition improved Monday after doctors drained excess fluid from around his lungs, according to statements from South African President Jacob Zuma’s office.

Mandela had a “restful day,” according to doctors, and will continue to receive treatment, Zuma’s office said.

Mac Maharaj, a spokesman for Zuma’s office, said Mandela was breathing “without difficulty.” The nation’s first black president has been hospitalized in the capital Pretoria for pneumonia.

Mandela, 94, was admitted for his second hospital stay this year before midnight local time on March 27, less than three weeks after a check-up. His health took a “downturn” that day and he was brought to the hospital to prevent the infection from spreading, Maharaj told Johannesburg-based broadcaster eNCA on March 28.

“We will be keeping him in our thoughts and prayers, and his entire family,” President Barack Obama said after meeting with African leaders in Washington on March 28, according to a White House transcript. “He is as strong physically as he’s been in character and in leadership over so many decades, and hopefully he will come out of this latest challenge.”

Mandela’s lung infection developed into a pleural effusion, which was tapped, Maharaj said in a statement yesterday. He said the former president was responding to treatment and was comfortable.

The Nobel Peace Prize winner was hospitalized from Dec. 8 to 26 to treat a lung infection and have gallstones removed. He contracted tuberculosis while imprisoned on Robben Island during his 27-year incarceration for fighting white minority rule.

Mandela led South Africa for five years after the African National Congress, or ANC, won the first all-race elections in 1994 that marked the end of apartheid.