The provisional results on Friday from the few thousand voters in the Congolese diaspora showed President Felix Tshisekedi with a comfortable lead over challengers.
The CENI election commission said results cast within Congo by its 44 million registered voters would be released from Saturday.
At a news conference in the capital Kinshasa, CENI president Denis Kadima again rejected criticism by the opposition and independent observers that the extended vote had been chaotic and lacked credibility.
Disputed elections have often sparked unrest in Africa's second-largest country, which is also the world's third-largest copper producer and the top producer of cobalt, a key component in electric car batteries.
The provisional results showed President Felix Tshisekedi with a comfortable lead over challengers. (AP PHOTO)
The presidential and legislative elections on Wednesday were derailed by delays in delivering election kits and malfunctioning equipment.
People also struggled to find their names on registers, while violence disrupted the poll in other places.
Commenting on the election for the first time on Friday, US election monitoring group, the Carter Center, noted "there was a lack of confidence in the process, stemming in part from previous elections, as well as from gaps in transparency, especially regarding the voter register".
Voting for some was extended into Thursday, prompting five opposition presidential candidates to call for a new election, saying the extension was unconstitutional.
Both opposition and Congolese independent observer groups have said voting unfolded in a way that could affect the credibility of results.
The CENI has set a December 31 deadline for the release of full provisional results, but it is not clear if this will change due to the unexpected voting extension.
The Carter Center called on the commission to post results at a local level and upload polling station results to its website to ensure the credibility of the process.
Speaking on radio station Top Congo FM, the commission vice-president Didi Manara said on Thursday the logistical setbacks on election day were out of the CENI's control and had nothing to do with bad planning.
He noted Congo had extended voting to a second day in parts of the country during the 2011 election.
The tumultuous election day capped a campaign that was also marred by violence that led to the deaths of at least 19 people, according to figures from the Carter Center.
Opposition presidential candidate Moise Katumbi, whose team has been monitoring the vote-count, said on Thursday that results so far showed him in the lead.
The vote will determine whether Tshisekedi serves a second term after a first five years in office marked by economic hardship and spiralling insecurity in Congo's rebel-plagued east.
