Hage Geingob has been in power for nine years.   / Photo: Reuters

Namibian President Hage Geingob has thanked Namibians and well wishers after undergoing a medical procedure on his heart in neighbouring South Africa.

He underwent what the Namibian presidency described as a ''minor'' procedure last Friday after a routine medical checkup had detected a mild aortic stenosis - narrowed heart valve that obstructs blood flow, the presidency had said in a statement.

The president, 81, was treated in South Africa because the procedure was unavailable locally and is expected to resume his duties on Tuesday, it added.

Geingob tweeted on Sunday of his "sincere gratitude for the uplifting messages" he received during the period.

"Please be assured that the President is in good spirits and appreciates every message of care and support throughout this period," his office said in a statement on Sunday.

Geingob is serving his second term after rising to power in the November 2014 presidential elections. He is not eligible to contest in the next presidential election due to be held next year.

TRT Afrika and agencies