The president celebrated his 68th birthday Saturday. Mr. Atta Mills served as president as Ghana began grappling with how to deal with its newfound oil wealth from offshore fields discovered in the last five years. The country, whose economy has been fueled by gold, cocoa and timber exports in the past, hopes to put the oil money to good use, mindful of how nearby Nigeria suffered through military dictatorships and widespread corruption over its oil wealth.
Mr. Atta Mills traveled to the United States in March and met for a meeting with President Obama at the White House. He also traveled to the United States in April as well, as rumors about his health began to circulate Ghana.
A government official in neighboring Ivory Coast said that he saw Mr. Atta Mills around six months ago in Ethiopia during an African Union meeting.
"We are hearing that he died of cancer of the throat. I saw him in Addis Ababa - not this meeting, but the one maybe six months ago," said the official, who requested anonymity because he was not authorized to speak to the media. "He was walking slowly. I am surprised to learn that he is only 68. He looked much older."
Still, the official said that no one suspected that he was gravely ill. "Yes, his death is a surprise - it's six months before the election, and he was a candidate."
Opposition newspapers had recently reported that he was not well enough to run for a second term.
Mr. Atta Mills was elected in a 2008 runoff vote - his third presidential bid - and was to run for a second term in December. He campaigned on a platform of change, arguing that the western African country's growth had not been felt in people's wallets.
Sen. Chris Coons (D., Del.), chairman of the Senate Foreign Relations subcommittee on African affairs, said in a statement: "Dedicated to improving the lives of his people and his beloved country, President Mills worked to promote economic growth and strengthen democratic institutions. As an academic and a former law professor, he demonstrated a deep and passionate commitment to transparency, rule of law and human rights."