JAKARTA - Indonesians are in for a long wait for the results of Wednesday's (April 17) polls, after the elections commission said it may take up to 35 days for the tally to be completed.

Indonesia's General Elections Commission (KPU) chief Arief Budiman told reporters on Thursday that the "real counts" are ongoing and being conducted in stages - first at the polling stations and then consolidated at a national level.

"KPU is granted a maximum of 35 days," Mr Arief said, but he added that he was also not ruling out the possibility that the process could be completed faster.

Early quick counts have put President Joko Widodo on track for re-election, but while he acknowledged the unofficial results, Mr Joko has also repeatedly called on supporters to wait for the official results from the KPU.

His rival Prabowo Subianto, however, has disputed the quick counts and continued to claim victory, setting the country on course for a tense period ahead of the official announcement by the elections commission.

Mr Prabowo, who has the support of several Islamist groups, will be appearing at a mass gathering in South Jakarta on Friday, after the Muslim noon prayers to mark the end of a peaceful elections.

Security is high due to concerns of unrest and a repeat of the mass street rally that hardliners held in downtown Jakarta in December 2016.

More than 192 million Indonesians were eligible to vote at the 2019 presidential and legislative elections.

Held on the same day for the first time in Indonesia, the event is arguably the world's biggest single-day elections ever held.

The surprise high turn-out at the polls means that possibly 80 per cent, or more than 150 million people, voted for the presidency and representatives in four other levels of government across the country.