It's a runoff to fill the presidency in Colombia, as none of the six candidates running for office Sunday managed to get the 50 percent plus one vote required to be elected.

Sunday's vote in the South American nation was a boiling point after years of deep polarization that has been simmering. Colombians have been grappling with how to go on with their future, as they remain uncertain about the best way to confront the country's past.

The past includes five decades of war with the Revolutionary Armed Forces of Colombia, a Marxist guerrilla group known as the FARC. Sunday's vote is the first presidential election since the signing of a peace accord between the Colombian government and the guerrilla group -- a deal that formally ended a war that left 220,000 dead and 7 million displaced, but still failed to win over voters who rejected the accord in a late 2016 referendum.

The deal, along with Colombia's growing refugee and border crisis, was one of the main issues on voters' minds Sunday. It's the legacy of current president Juan Manuel Santos, who was term-limited from running again.

Under Colombian law, if a candidate doesn't get enough votes to win outright, a runoff is called between the two candidates with the most votes. This year, the two still in contention for the June 17 runoff are right-wing candidate Ivan Duque and left-wing candidate Gustavo Petro, who have campaigned on radically disparate platforms and propose very different approaches to the controversial peace deal signed with the FARC.

Duque, an investor-friendly former senator who campaigned against the peace accord, took first place with 39 percent of the vote. Petro, a former guerrilla leader and recent mayor of the capital city Bogota, came in second with 25 percent of the vote.

In his first interview after results were announced, Duque -- who has the support of former President Alvaro Uribe Velez, a celebrated if controversial right-wing figure in Colombian politics -- asked voters to give him a chance to take the country out of its complicated past and into the future, promising to do away with Uribe-era complaints.

"We have to focus on the things we agree on, instead of on the things that divide us," he said. "I'm fully open to [enter into] dialogue with any political groups and, above all, with the people."

Historically, many Colombians have been wary of left-leaning politicians who they've seen as friendly to the guerrilla groups with whom they've spent 50 years at war. But disenchantment with years of right-wing rule has led many, particularly young people, to support the left-wing candidate Petro.

In his first interview after the results were announced, Petro walked back some of his more radical proposals -- some of which had detractors comparing the former mayor to the late Venezuelan president Hugo Chavez, whose economic and social policies have been blamed by many for the current humanitarian crisis in Venezuela.

Moving closer to the center, Petro said he would no longer call for changing the country's constitution, or for the possibility of the government taking over private corporations. Petro also made one of his boldest moves yet -- and one he had been reluctant to make until Sunday -- calling the government of current Venezuelan President Nicolas Maduro a dictatorship.