Ghani's chief opponent rejected the result and said he would form his own government.
Afghanistan's Independent Election Commission (IEC) declared Tuesday incumbent Ashraf Ghani winner of the Sept. 28 presidential election, his main rival Abdullah Abdullah rejected the result and pledged to form his own government.
Ghani secured 50.64 percent of the vote, the IEC said, while Chief Executive Abdullah, came second with 39.52 percent. Yet the runner up said he won the election and would form the government.
“The result they [IEC] announced today was a result of election robbery, a coup against democracy, a betrayal of the will of the people, and we consider it illegal,” he told a news conference in the capital Kabul.
"Our team, based on clean and biometric votes, is the victor and we declare our victory. The fraudsters are the shame of history and we announce our inclusive government."
The vote took place amid a low turnout five months ago, and the counting process was marred by accusations of rigging, technical problems, attacks, and protests from the candidates.
The IEC announced preliminary results in December in which Ghani won by a slight margin, but Abdullah Abdullah contested the outcome and called for a full review. Ghani rejected the allegations.
2/2 We do not accept the fraudulent results. We are announcing our victory. We will now form an inclusive government. We call on all our compatriots who believe in democracy & fairness to stand with us. God protect our country. pic.twitter.com/FRA3eVOcfp
In the 2014 polls, the same presidential candidates ended in a deadlock accusing each other of massive fraud. The United States (U.S.) arbitrated then the dispute and settled in a power-sharing system that made Ghani president and Abdullah his chief executive.
Since then, the relationship between the two men has been marked by an intense struggle for power.
The announcement of the result also comes as the U.S. and the Taliban - which has been fighting the US-led NATO forces in the country since their regime was toppled in 2001 - near an arrangement in Doha, which officials on both sides say could be announced soon if a seven-day reduction in violence is achieved with success.
The encounter is aimed to pave the way for critical talks between the country’s official politicians and the Taliban. The latter has always refused to negotiate with the government, which they consider a U.S. puppet.
Taliban also rejected Ghani’s reelection as a threat to the peace process. The reelected president appeared after the announcement of the result among supporters in Kabul, where he said his team will bring peace to the country.
"It's time to make Afghanistan united," he said, urging the Taliban to participate in the process.
Ghani, from central Logar Province, was born in 1949. He has a doctorate in anthropology from Columbia University.
Except for a brief teaching stint at Kabul University in the early 1970s, he lived in the U.S., where he was an academic until joining the World Bank as a senior adviser in 1991.
He returned to Afghanistan after 24 years abroad when the U.S. invaded the country in 2001 to remove the Taliban.
Ghani served as the head of Kabul University before joining the government of President Hamid Karzai. In 2010, he led the long process to transfer the security of the country from the U.S. forces to the Afghan forces.