John Atta Mills, the President of Ghana, died at the age of 68 Tuesday. A statement from his office, said the leader, who won international praise for his success in stabilizing democracy in Ghana, was in the hospital, but no further details were given.
"It is with a heavy heart that we announce the sudden and untimely death of the President of Republic of Ghana," a statement from Mills' office said, according to the AFP.
His office said he died at a hospital in Ghana's capital city, Accra, but did not give a cause.
According to BBC News, the President had been suffering from throat cancer, but his office did not confirm that in its statement.
Under Ghana's constitution, Ghana's Vice President, John Dramani Mahama will be sworn into replace Mill, Reuters reports.
John Atta Mills ruled Ghana since 2009.
He was elected in 2008 after being defeated twice by former President John Kufuor in 2000 and 2004.
Mr. Kufuour stepped down after his second term as Ghana allows for only a two-term limit as president.
Mills beat Nana Akufo Addo in 2008.
The BBC's Sammy Darko, who was at the hospital with Mills Tuesday, said his voice had been weakening within in the last few months.,
According to the AFP, Mills visited the US in March for a "routine" medical checkup.
During that visit, US President Barack Obama also welcomed Ghana's leader to the Oval Office, and praised him and his country as a "good-news story" in Africa, Reuters reports.
World leaders such as Nigerian President Goodluck Jonathan, have been expressing their condolences on Mills' untimely death.
In a statement Tuesday, Jonathan assured the people of Ghana "of the sympathy and solidarity of the people of Nigeria as they mourn late President Mills, who did his best during his tenure to carry forward the process of democratic consolidation and socio-economic development in Ghana," The AFP reports.
According to BBC News, under President Mills, Ghana was one of the world's most successful oil producers. He planned to seek re-election in December.