South African President Cyril Ramaphosa appealed for the release of the delayed vote count in the Democratic Republic of Congo.
Ramaphosa's call comes amid growing concerns that violence could break out. It also follows a meeting with Zambian President Edgar Lungu to discuss the situation in DR Congo.
The polls, which were supposed to have taken place two years ago, was finally held on 30 December. Twenty one candidates vied to replace President Joseph Kabila, who has been in power for almost 18 years.
The result of the vote was initially expected to be announced on Sunday. It is now expected to be made public later on Wednesday.
"Presidents Ramaphosa and Lungu have called on CENI [DR Congo's National Electoral Commission] to speedily finalise the vote tabulation and release the election results in order to maintain the credibility of elections," the department of international relations said in a statement.
The heads of state also called on political parties and the Congolese people to remain calm.
"The two Presidents underscored that the delay in releasing the results of the elections can lead to suspicions and compromise peace and stability of the country."
Ramaphosa, in a separate statement issued by the Presidency, congratulated Madagascar for running a peaceful run-off presidential election.
Andry Rajoelina emerged as the new president of the country.
In the December 19 vote, Rajoelina took 55% and Marc Ravalomanana won 44%, according to the final results. Both are former presidents.
"Ramaphosa ... praised both leaders, Mr Rajoelina and Marc Ravalomanana who were running for the runoff presidential election for working together in ensuring that the interests of the people of Madagascar come first by accepting the run-off results."
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