Colombia's new leader could wreck Farc deal

Colombia's President Elect Ivan Duque. Photo / AP

Conservative Ivan Duque captured Colombia's presidency, bringing to power a US-educated 41-year-old whose victory promises an aggressive new era in the drug war and could upend a historic peace deal.

Duque was elected by 54-42 per cent. Turnout was 53 per cent of voters, higher than in recent elections.

By winning yesterday's vote, Duque stopped the rise of his leftist opponent, Gustavo Petro. The former guerilla-turned-senator-turned-Mayor of Bogota had pledged a break with the "militaristic" drug war backed by the US. In contrast, Duque's win could herald a return to more forceful tactics.

The US has spent US$10 billion in two decades fighting coca growth here - only to find it higher now than at the launch of the campaign. US officials see Duque - a protege of right-wing former President Alvaro Uribe, who launched a widespread offensive against guerrillas and narco-traffickers in the 2000s - as a reliable partner. He could bring back aerial spraying, banned in 2015 for health reasons.

Duque - who also pledged to lower corporate taxes and boost police forces - brings with him this nation's first female vice-president, former Defence Minister Martha Lucia Ramirez, 63.

Yet his victory endangers the 2016 peace accord struck with Farc, for which outgoing President Juan Manuel Santos won the Nobel Peace Prize.

Duque has stopped short of saying he would tear it up. But he has called for "structural changes" - in particular that the group's former leaders who have been granted seats in Congress should be tried for war crimes. Critics fear such changes could kill the already-deteriorating peace process.

"The peace accord was a lie," said Rodrigo Pimentel, 72, a Bogota doctor who voted for Duque. "Internationally, everyone was in favour of it. But not here. How can the same people who killed so many, who were narcotraffickers, sit in our Congress?"