Nicolas Maduro, the chosen heir of late Venezuelan leader Hugo Chavez, won Sunday’s presidential election by less than 2 percentage points, according to official results.
Henrique Capriles, the candidate of the unified opposition, refused to concede defeat and demanded a full recount.
“We are talking about the country (divided) in halves,” Mr. Capriles said.
Mr. Maduro received 50.76 per cent of the votes to 49.07 per cent for Capriles, with more than 99 per cent of the ballots counted, official results showed. Turnout was more than 78 per cent of eligible voters.
Less than 300,000 ballots out of 18.9 million registered voters separated the two candidates.
“These are the irreversible results,” Electoral Council president Tibisay Lucena said.
She stressed that the authorities would not have published the results if there was a possibility they could still change.
“Venezuela has spoken today, and it has spoken loud,” Mr. Lucena said.
Mr. Maduro, 50, proclaimed victory immediately after the announcement, but also called for a recount to ensure the legitimacy of the election.
“Be sure that if the Electoral Council had said a different candidate won I would still be here accepting defeat,” he told supporters.
As he did throughout the brief election campaign that followed Chavez’s death, Mr. Maduro presented himself as the heir to Venezuela’s leader of 14 years.
“This is the first time that the giant (Chavez) is not a candidate. He left his son, and now his son is going to be president,” Mr. Maduro said, referring to himself.
Mr. Maduro said Mr. Capriles had called him to propose a pact in light of the very close results, which Mr. Maduro refused.
“He told me his vision, I told him the truth,” Mr. Maduro said. “That’s life.”
Mr. Capriles denied having proposed such a pact and slammed his rival. “I don’t make pacts with lies or with corruption,” he said.
“Today’s great loser is you, you and what you represent,” he told Mr. Maduro.
Mr. Maduro called for “peace” in deeply polarized Venezuela.
“Let no one fall for provocations, but let no one create provocations,” he said. “Let this be no excuse to call for violence.” Maduro stressed that Chavismo has won 17 elections out of the 18 they have faced over the past 14 years, and that they conceded defeat in the referendum by only a small margin.
Mr. Capriles pointed out that the opposition had won in several of the country’s states as well as most large cities.
Mr. Maduro’s overall victory “does not reflect the country’s reality,” Mr. Capriles said.
Polling stations, which opened at 1030 GMT closed 12 hours later, although people in line at that time were allowed to cast their ballots.
Both sides praised the high turnout.
The opposition complained of irregularities in the voting process, but Mr. Lucena said there were only isolated incidents.
Mr. Maduro was set to be appointed with a six-year mandate, to complete the one that Chavez started in January.
Nearly 14,000 polling stations across the country were equipped with electronic voting.
A total of 3,435 local observers and 240 international observers were on hand to monitor the voting process, including former presidents Leonel Fernandez of the Dominican Republic and Alvaro Colom of Guatemala.
Mr. Chavez beat Capriles with 55 per cent of the vote in the October presidential election, but his health worsened from mid-December and he was never formally inaugurated for his new six-year term. He died at a Caracas hospital on March 5.
Venezuela is struggling with one of the world’s highest annual inflation rates at more than 27 per cent, although its treasury can draw on an income of billions of dollars from the oil industry. The country is one of the world’s largest producers of crude oil.