Ghana's Vice President John Dramani Mahama has taken the presidential oath of office just hours after officials announced the country's leader had died.

President John Atta Mills died Tuesday at a military hospital before he could finish his first term in office. He had planned to seek re-election in December's poll.

State-run television in Ghana carried John Mahama's swearing-in live from parliament Tuesday evening. He raised a golden staff of office above his head.

The swift adherence to Ghana's constitution on succession underlines the country's reputation as one of the most mature democracies in the region.

Atta Mills took power in 2009, marking the country's second successful handover of power from one legitimately elected leader to another.