According to the country's electoral authority, if neither of the two leading presidential candidates could ensure a first-round victory, the second round will be held on April 2.
With the last ballots trickling in from Sunday's election, ruling party candidate Lenin Moreno had a little over 39 percent of the votes and an nearly 11-point lead over conservative Guillermo Lasso, a former banker who finished second in a field of nine candidates.
Moreno got slightly more than 39 percent of all votes in Sunday's election, while Lasso trailed by almost 11 points at 28 percent, officials said.
On Monday Lenin Moreno, who was a former vice-president under the outgoing Rafael Correa, said he does not see why the opposition would cry fraud.
"Fraud is coming", he warned on Twitter Monday.
Yesterday at 9:30am Lasso arrived at the Universidad Tecnologica Equinoccial in the north of Quito to accompany his running mate Andres Paez, where he was greeted by throngs of supporters of his Movimiento CREO.
The third-placed candidate is conservative former lawmaker Cynthia Viteri, 51. Two showed a second round, with Moreno failing to reach the 40% threshold, and two showed him reaching 42% and 44%.
"No one has denounced a fraud", Vega said, adding that it is hard to believe "that the National Electoral Council would have invited more than 200 observers for a fraud".
On Monday, Moreno told local television that votes from Manabí province and from overseas would likely push him over the line.
Ecuadoreans are growing impatient at the slow pace of vote counting with the results of the presidential poll delayed until Wednesday or Thursday.
A second round of voting in Ecuador's election for president will be required, the head of the country's National Election Council (CNE) announced Tuesday, despite five percent of the vote yet to be counted. Highly popular after spending more than $300 billion on social programs, infrastructure and expanding the government's role in South America's seventh-biggest economy, he had to ramp up government debt to maintain spending when the price of oil, the OPEC member's top export, plunged after 2014. "Lasso will be the next president, that's it, out with Correa". He has also promised to push for Ecuador to join the Alliance of the Pacific trade block, which includes key neighbors Chile, Peru, Colombia, and Mexico.
Those results could also decidel whether WikiLeaks founder Julian Assange will be able to stay at the Ecuadorean embassy in London. Longtime political rival Jaime Nebot, the conservative mayor of Guayaquil, said he would call for a massive protest to ensure the will of the voters was respected. The relationship between Assange and the Ecuadorean government has been rocky at times.
"We're not Cuba or Venezuela, out with Correa!" they chanted.
Meanwhile, in Ecuador, all eyes are on the CNE as results trickle in.
Mr Moreno was quick to declare himself the victor based on inconclusive exit polls and called on Mr Lasso to recognise defeat. He pointed out that the official announcement of a runoff in Ecuador will be made once the 100 percent of the minutes are counted.