Kabul , Afghanistan ( CNN ) -- Ashraf Ghani Ahmadzai is the new President of Afghanistan , and his rival , Abdullah Abdullah , is CEO , Afghanistan Independent Elections Commission chairman Ahmad Yousuf Nooristani announced in a news conference in Kabul on Sunday . Nooristani did n't disclose the percentage of their votes from the June runoff election . He also did n't take any questions from journalists . Ghani and Abdullah signed a power-sharing agreement earlier Sunday after months of infighting over allegations of voting fraud and manipulation . The U.S. State Department congratulated both candidates , as well as the people of Afghanistan , `` who courageously went to the polls to vote on April 5 and again on June 14 , defying Taliban threats to exercise their right to vote and to take their part in advancing democracy in Afghanistan , '' according to a statement . The statement also recognized incumbent President Hamid Karzai for 13 years of `` strong leadership . '' The lengthy dispute between Ghani and Abdullah had put off the selection of a successor to Karzai and raised fears of increased instability in the fragile , war-torn country . But the two rivals embraced after signing a deal for a national unity government in a televised ceremony in the capital , Kabul , on Sunday . Under the agreement , Ghani will create by decree the position of chief executive officer for the runner-up . The CEO role will have prime ministerial functions until the constitution can be amended to create a permanent position of prime minister . The deal also calls for the two candidates ' teams to share senior government positions equally between them . The political impasse in Afghanistan this year had come as the Taliban continued to mount deadly attacks on high-profile targets and fought fiercely for control of important areas . As the U.S.-led war effort against the militants winds down , most NATO troops are due to withdraw from Afghanistan by the end of this year . 'Three months of squabbling ' The presidential election was held on April 5 and was followed by a runoff vote in June after the first round proved inconclusive . The election was aimed at bringing about Afghanistan 's first democratic transfer of power , but the accusations of fraud and manipulation put that goal in peril . In July , Abdullah and Ghani had come to an agreement , brokered by U.S. Secretary of State John Kerry , to accept the result of a nationwide audit and form a unity government . But earlier this month , the two candidates showed signs of backing away from that deal . Kerry described the signing of the deal Sunday as `` a moment of extraordinary statesmanship , '' saying Ghani and Abdullah had `` put the people of Afghanistan first . '' U.N. Secretary-General Ban Ki-moon said the deal `` paves the way for a stable and more prosperous future for the country . '' `` The new government will face serious challenges , and I urge the President-elect , the Chief Executive Officer , Dr. Abdullah Abdullah , and all political actors in Afghanistan to quickly form the government of national unity , '' Ban said in a statement . The State Department statement said that while the audit was able to `` identify fraud that was significant in both scope and sophistication , '' the audit process was unable to resolve all grievances . Nonetheless , the election results are legitimate , and the State Department will support the administration 's efforts to make electoral reform a chief priority , the statement said . The White House and the U.N. Secretary-General 's Special Representative for Afghanistan , Jan Kubis , both expressed support for the new government . But questions remain about how effective the new arrangement is likely to be . `` It took three months of squabbling and political infighting to get to this point , '' Yaroslav Trofimov , the Afghanistan and Pakistan editor of The Wall Street Journal , told CNN . `` It 's anybody guess how well they will manage to actually govern together , considering all the bad blood . '' CNN 's Masoud Popalzai reported from Kabul , and Jethro Mullen reported and wrote from Hong Kong . CNN 's Eliott C. McLaughlin , Nana Karikari-apau , Christabelle Fombu and Tom Dunlavey contributed to this report .
NEW : ` ` The new government will face serious challenges , '' police chief says . # ##ment . : Audit found ` ` significant '' fraud , but results legitimate . Sharif and Sharif agreed to national unity government earlier in March . The agreement comes after months of dispute between the two candidates .