Ivory Coast's President Alassane Ouattara said Wednesday it was crucial that Mali's presidential election be held as scheduled on July 28 amid doubts that the divided nation will be ready for the vote.
Ouattara made the comments at the opening of a summit of the 15-nation Economic Community of West African States (ECOWAS) in Nigeria's capital.
"The Malian people must be able to count on the experience of the political class and the support of the international community to ensure that the holding of these elections on July 28 is irreversible," said Ouattara, the current ECOWAS chief.
Mali's first-round presidential election is seen as crucial to reuniting the nation, shaken by an 18-month political crisis that saw French forces intervene in January to push out Islamist rebels who had seized the north.
But the country's election commission has expressed doubts it will be ready to hold the vote on July 28, with some 500,000 people still displaced after the conflict.
Nigeria's President Goodluck Jonathan, in his opening speech, said there was "a financial gap of $25 million" (19 million euros) to properly fund Mali's vote.
He urged foreign donors "to intensify their assistance".
The March 2012 coup in Mali toppled president Amadou Toumani Toure and created an opening that allowed groups allied to Al-Qaeda to seize the vast desert north.
Many observers have raised concerns over persistent security challenges ahead of the polls.
France, which plans to start withdrawing most of the 4,500 troops it sent to Mali, has been pushing for quick election in the hopes of restoring order.
Mali has been led by an interim government since the coup.
Also on Wednesday, a key Malian political player said the country was not ready to run a credible election and withdrew from the presidential race.
Tiebile Drame, chief negotiator in a ceasefire deal with rebels that was a crucial precursor to the elections, told reporters in the capital Bamako that "the conditions for a fair vote are not in place".
He has petitioned Mali's Constitutional Court for a postponement, and said going ahead with the July 28 date would be "to deny many Malians their right" to vote.
The ECOWAS summit, which ends Thursday, is also focusing on Guinea-Bissau, set to hold elections in November following a coup last year.
Parliamentary elections have been scheduled for November 24, with ECOWAS nations having deployed some 750 troops to the country to provide security.
Both Ouattara and Jonathan urged foreign donors to unfreeze aid to the nation, which has been plagued by chronic instability.
South American drug cartels have also turned it into a hub of cocaine trafficking for west Africa.
"The continued isolation of Guinea-Bissau and the freeze on international development assistance are aggravating the fragile economy," said Jonathan.
He insisted the block on aid had hampered regional efforts against drug trafficking.
Ouattara called on world governments to lift their aid bans and fund the transitional government's election plan.
There has been a series of military coups in Guinea-Bissau, with the latest the overthrow of the regime of premier Carlos Gomes Junior in April 2012.