Former finance minister Ashraf Ghani was declared Afghanistan’s next president on Sunday, hours after signing a power-sharing deal with his rival Abdullah Abdullah that ended a prolonged standoff over the disputed result.

The “unity government” deal paves the way for a crucial bilateral security agreement (BSA) governing the presence of American troops in Afghanistan beyond 2014, with Washington voicing optimism that it will be signed soon.

Afghan presidential candidates Abdullah Abdullah (L) and Ashraf Ghani Ahmadzai shake hands after signing a power-sharing agreement at the Presidential Palace in Kabul on September 21

Allegations of massive fraud in the June 14 vote sparked a political crisis as both candidates claimed victory, paralysing the country at a key moment with US-led troops winding down their 13-year war against the Taliban.

When the “unity government” deal was finally signed, Ghani embraced Abdullah briefly at a low-key ceremony in the presidential palace that lasted less than 10 minutes.

Abdullah will become “chief executive officer” (CEO), a role similar to prime minister — setting up a tricky balance of power as Afghanistan enters a new era.

Neither candidate spoke at the palace ceremony, and it remained uncertain when they would address the nation or when the unity agreement would be officially published.

“The Independent Election Commission declares Dr Ashraf Ghani as the president, and thus announces the end of election process,” commission chief Ahmad Yousaf Nuristani later told reporters.

“During the election process fraud was committed from all sides. That has concerned people.”

In a move likely to trigger complaints over transparency, Nuristani gave no figures for the winning margin, turnout or the number of fraudulent ballot papers thrown out in an UN-supervised audit that checked every individual vote.

Ghani was widely acknowledged to be on the brink of the presidency after coming well ahead in preliminary results released before the audit began.

Under the constitution, the president wields almost total control, and the new government structure will face a major test as the security and economic outlook worsens.

“Hamid Karzai wishes the elected president Dr. Ashraf Ghani and the CEO Dr. Abdullah Abdullah success based on the agreement between them,” said a statement from the outgoing president.