Indonesian election officials were expected on Tuesday to officially declare Jakarta Governor Joko "Jokowi" Widodo the winner of a hotly contested presidential election in which his rival has alleged mass cheating.
Private tallies show Jokowi beat former special forces chief Prabowo Subianto by about five percentage points.
Prabowo has refused to concede defeat and is expected to challenge the result in the Constitutional Court, though experts say such an appeal is unlikely to succeed.
A spokesman for the Election Commission said the announcement would be made by 6 p.m. (7 a.m. EDT).
Outgoing President Susilo Bambang Yudhoyono urged whoever loses the closest presidential race in Indonesia's history to acknowledge the outcome to avoid violence in the world's most populous Muslim nation.
"Admitting defeat is noble," the president told reporters on Monday, in a clear reference to Prabowo.
Hundreds of thousands of police and military are on heightened alert across the vast archipelago of 240 million people, the world's third largest democracy. There have been no reports of major violence.
"There are a lot of rumors of instability and unrest but cautiously I'm confident that it is implausible," said Tobias Basuki, a political analyst at the CSIS think-tank.
Markets have largely brushed off the uncertainty in Southeast Asia's largest economy and have rallied on the likely Jokowi win. A protracted wrangle over the election outcome could undermine confidence.
"The possibility of overturning the election result is very slim. Investors will instead focus on the presidential cabinet, which the new president should announce by October," said Sebastian Tobing of Jakarta-based brokerage Trimegah Securities.
The Jakarta Stock Exchange is trading near a one-year high, closing up nearly 1 percent on Monday. The rupiah has also strengthened against the dollar, gaining 0.4 percent to 11,567.
Jokowi has a film-star following.
Born in poverty, he has stormed his way to the top rungs of leadership with a clean image and a reputation for competence in local government, in complete contrast with the autocracy, corruption and power politics that have weighed down the country for decades.
Prabowo's reputation as a strongman and his vow to reverse the indecisiveness of the outgoing government won him a large following among people yearning for a return to old-style politics.
Candidates can lodge complaints with the Constitutional Court, as did the losers of the previous two elections since strongman ruler Suharto was forced to step down in 1998 after more than three decades in power.
The Court must return a verdict on any challenge within two weeks and it cannot be appealed.
"It is going to take a lot to push this to the Constitutional Court. Prabowo's camp has to prove there was massive, systemic fraud," Basuki said.
Election officials said reports of irregularities had been investigated, but the number of disputed votes is limited to thousands of cases.
Analysts believe a reversal of up to seven million votes would be needed to overturn Jokowi's lead and hand victory to Prabowo.