Namibian President Hage Geingob died Sunday while receiving medical treatment, his office announced.

In a post on the social media platform X, formerly Twitter, the Namibian presidency said Geingob's medical team at Lady Pohamba Hospital did its best to help him, but Geingob died with his wife, Monica Geingos, and children by his side.

Geingob was undergoing treatment for cancer. The 82-year-old had a colonoscopy and a gastroscopy on Jan. 8, followed by a biopsy, his office said last month.

Angolo Mbumba, Namibia's acting president, called for calm, saying in the same post that the “Cabinet will convene with immediate effect in order to make the necessary state arrangements in this regard.”

Geingob, who was president of the southern African nation since 2015, was set to finish his second and final term in office this year. In 2014, he said he had survived prostate cancer.

Namibia is set to hold elections to choose a new leader in November.