"I am feeling much better but I have to go to South Africa this afternoon. I need to go for further tests and then if there will be need for other procedures such as surgery they will tell us," Lungu said on Tuesday.
"I hope to come back alive, no one wants to die," he said, laughing.
Lungu, 58, was discharged from the hospital on Monday where he had been receiving treatment after feeling unwell while at an International Women's Day event in the capital on Sunday.
Lungu assumed the presidency in January after winning a narrow victory in an election to replace former leader Michael Sata, who died in October, while undergoing treatment in London