Outgoing Afghan President Hamid Karzai on Tuesday pressured rival candidates to succeed him to end delays to a promised power-sharing deal after a disputed election and prevent a crisis from escalating further.

The crisis surrounding the presidential election has dragged on since the June 14 run-off vote, with both top candidates declaring victory and alleging fraud.

The tension threatens to destabilise Afghanistan and provide opportunities for the Taliban insurgency just as most U.S. and allied troops prepare to leave by the end of the year.

In rare public remarks on the crisis, Karzai urged the crowd at a ceremony to help him pressure the candidates, Ashraf Ghani and Abdullah Abdullah, to agree on details of a unity government which they had promised in a deal with U.S. officials.

“Call on them now and call on them loudly,” Karzai said at a ceremony honouring a revered anti-Taliban commander. “Tell them that we will not let them leave (the venue) unless they reach an agreement and rescue the country,” Karzai added, in one of his strongest public statements on the row. The crowd responded with shouts, and Karzai called out: “Louder!”

Ineligible to serve a third term, Karzai has been in private meetings with both candidates to try to end the crisis. In late July, both candidates pledged in an agreement with U.S. Secretary of State John Kerry to respect the final results and form a unity government.

Under the agreement, the losing candidate would become a chief executive with significant authority. However, the exact powers of the new position have been a sticking point in talks between the two camps.

Abdullah on Monday said negotiations were still deadlocked. He again alleged massive fraud and said he would never accept confirmation of the preliminary result showing Ghani won the run-off election.

An audit of all ballots finished last week, and the U.N.-monitored process is now determining how many ballots will be disqualified. Final results are expected in coming days but the exact date is unclear.

There are concerns the election crisis could inflame ethnic tensions that fuelled Afghanistan’s previous civil wars.

Abdullah is seen as drawing most of his support from the country’s Tajiks and Hazaras centred in the north while Ghani is a member of the Pashtuns based in the south and east. Karzai is Pashtun, as is the Taliban leadership.

Abdullah, a former foreign minister under Karzai, on Monday called for calm ahead of Tuesday’s commemoration of the 2001 assassination of legendary Tajik resistance commander Ahmad Shah Massoud. Abdullah was a longtime Massoud deputy.

Massoud’s assassination by al Qaeda came just few days before the Sept. 11 terrorist attacks on the United States. Those attacks led to the U.S.-led invasion to oust the Taliban’s radical Islamist regime for hosting Osama bin Laden and the rest of al Qaeda’s leaders.