Kabul ? Afghanistan’s election crisis deepened Saturday as President Hamid Karzai resisted international pressure to accept fraud rulings that could force him into a runoff with his main challenger.

Three more American service members were reported killed in separate bombings as the U.S. and its international partners sought a way out of Afghanistan’s political impasse, a crisis that threatens the legitimacy of the Afghan government and the future of the U.S.-led military mission.

A U.N.-backed panel had been expected to release findings Saturday from its investigation into allegations of widespread fraud — most of it favoring Karzai — in the Aug. 20 election.

Preliminary figures showed Karzai won with more than 54 percent of the vote.

Still, Karzai could face a runoff with his chief rival, Abdullah Abdullah, if the complaints panel invalidates enough ballots to push the incumbent’s total below 50 percent.

Announcement of the commission’s findings was delayed as commission members spent Saturday in meetings with Afghan election officials and double-checking calculations, according to people familiar with the talks.

Karzai has refused to commit to accepting the panel’s findings before they’re released, even though his campaign staff has expressed confidence that the president will remain above 50 percent, eliminating the need for a runoff.

Karzai’s stand has raised concern that he may challenge the findings, further delaying proclamation of a winner or the scheduling a runoff.

Afghan law declares the U.N.-dominated Electoral Complaints Commission the final arbiter on fraud allegations. However, Karzai supporters on the separate Independent Election Commission, which must order a runoff, have argued that the partial recount is beyond the normal complaint process and that the U.N.-backed panel does not have the final say.

A second round of balloting must be held before the coming of winter, which traditionally begins in mid-November. Once heavy snows fall in the mountain passes, a runoff would have to wait until spring, leaving the country in political limbo for months as the Taliban gains strength.

Fearing the political crisis will worsen, U.N. Secretary-General Ban Ki-moon, U.S. Secretary of State Hillary Rodham Clinton and British Prime Minister Gordon Brown have telephoned both Karzai and Abdullah in recent days to express concern over the impasse.

French Foreign Minister Bernard Kouchner; U.S. Sen. John Kerry, chairman of the Senate Foreign Relations Committee, and former U.S. ambassador to Afghanistan, Zalmay Khalilzad, were all in Kabul on Saturday for talks with Afghan leaders.

Kerry told the candidates “about the need for a legitimate outcome,” according to a U.S. Embassy official who spoke on condition of anonymity because of the sensitivity of the issue.

In taped remarks for broadcast today on CNN’s “State of the Union,” Kerry said it would be irresponsible for the U.S. to consider sending additional troops to the region to achieve a mission of “good governance” when the Afghan election is not yet finished.

A statement by the French Foreign Ministry said Kouchner traveled to Kabul “in the context of tension” brought on by the disputed election and urged all parties “to respect” the review process in the interest of the country.

At the same time, envoys were urging both candidates to strike a power-sharing deal to avoid a potentially divisive and costly second vote.

Officials familiar with the talks say the two sides are far apart on details, and it was unclear whether a power-sharing deal would be constitutional. The officials spoke on condition of anonymity because the issue is sensitive.

“They want us to establish a strong government, a coalition government,” said Mohamed Mohin Murstal, a member of parliament and a Karzai supporter. “Karzai has agreed that after the announcement of the results, he will give the opportunity for all political personalities to be involved in government — but not before.”

Karzai’s campaign spokesman, Waheed Omar, said the president is “not going to compromise the results of the elections into any sort of political deal.”