KABUL, Afghanistan (AP) — Afghanistan's two presidential candidates signed a power-sharing deal on Sunday that makes one president and the other chief executive, ending months of political wrangling following a disputed runoff that threatened to plunge the country into turmoil and complicate the withdrawal of foreign troops.

The incoming president — Ashraf Ghani Ahmadzai — and new Chief Executive Abdullah Abdullah signed the national unity government deal as President Hamid Karzai — in power since the 2001 U.S.-led invasion ousted the Taliban — looked on. The deal creates the new role of chief executive following weeks of negotiations on a power-sharing arrangement, after accusations of fraud in the June runoff vote.

The candidates signed the agreement at the presidential palace, then exchanged a hug and a handshake.

"I am very happy today that both of my brothers, Dr. Ashraf Ghani and Dr. Abdullah Abdullah, in an Afghan agreement for the benefit of this country, for the progress and development of this country, that they agreed on the structure affirming the new government of Afghanistan," Karzai said after the signing.

The deal is a victory for U.S. Secretary of State John Kerry, who first got the candidates to agree in principle to share power during a July visit to Afghanistan. Kerry returned to Kabul in August and has spent hours with the candidates, including in repeated phone calls, in an effort to seal the deal.

A White House statement lauded the two leaders, saying the agreement helps bring closure to Afghanistan's political crisis.

"This agreement marks an important opportunity for unity and increased stability in Afghanistan. We continue to call on all Afghans — including political, religious, and civil society leaders — to support this agreement and to come together in calling for cooperation and calm," the White House statement said.

Jan Kubis, the top U.N. official in Afghanistan, said the uncertainty of the past months took a heavy toll on Afghanistan's security, economy and governance. NATO said in a statement that it hoped both leaders could move forward "in the spirit of genuine political partnership."

The four-page power sharing contract says the relationship between president and chief executive — a position akin to prime minister — must be defined by "partnership, collegiality, collaboration, and, most importantly, responsibility to the people of Afghanistan."

It spells out the powers for the new chief executive position: participation with the president in bilateral meetings, carrying out administrative and executive affairs as determined by presidential decree, and parity in selection of key security and economic ministries.

The deal specifies that the president leads the Cabinet but that the chief executive manages the Cabinet's implementation of government policies. The chief executive will also chair regular meetings of a council of ministers.

An inauguration ceremony to see Ghani Ahmadzai replace Karzai as president and swear in Abdullah as chief executive was expected within days. Abdullah's spokesman Fazel Sancharaki said the event could be held on Sept. 29. The election commission said it would release official vote totals later Sunday.

As talks dragged on, Abdullah's mostly northern supporters had threatened to form a parallel government or react violently to any outright victory by Ghani Adhmadzai, a former finance minister and World Bank official whose power base is in the country's south and east. Ghani Ahmadzai said he always maintained that ethnic politics in Afghanistan demand some sort of power sharing deal and not a winner-takes-all government.

Abdullah believes he won the first round of the election back in April with more than 50 percent of the vote, which would have precluded a runoff. But the official results showed him winning about 45 percent of that vote in a crowded presidential field of 10, not quite enough for an outright victory.

He also believes he won a June runoff with Ghani Ahmadzai. But initial results totals showed Ghani Ahmadzai with about 56 percent of the vote. After the recount the election commission invalidated 1 million of the approximately 8.1 million cast in the runoff, suggesting that fraud was indeed widespread. Ghani Ahmadzai's winning percentage dropped to about 55 percent.

Though the White House statement said that "respect for the democratic process" is the only viable path forward for Afghanistan, the next Afghan government is more the product of negotiations than vote tallies.

Shekiba Hashimi, a lawmaker from the southern province of Kandahar, said she was happy not only as a member of parliament "but as a woman and a mother" that the candidates reached a deal and moved the country forward.

"We are in a very sensitive situation, not only from a security point of view or an economic or political point of view. The enemies of the Afghan nation were benefiting from this stalemate. Recent big and complex attacks in southern and southeastern provinces are examples," she said.

A power-sharing deal was almost sealed about a week ago, but Abdullah then demanded that no vote totals from the runoff be released.

U.N. and Afghan election officials spent weeks auditing the runoff results after allegations of fraud, a common occurrence over Afghanistan's last two presidential elections. Abdullah's side maintained the fraud was so sophisticated it was undetectable.

The U.S. has been pushing for a resolution so the next president can sign a security agreement that would allow about 10,000 U.S. forces to remain in the country after combat operations wrap up at the end of the year. Karzai refused to sign it; Ghani Ahmadzai has said he will.

The 13-year war against the Taliban has largely been turned over to Afghan security forces, a development that has seen casualties among Afghan soldiers rise significantly this year.

The U.S. and international community will continue to fund the Afghan army in the coming years but the Afghans themselves will have to fend off Taliban attempts to again take over wide areas of the country.