Colombia's presidential election will proceed to a runoff after right-wing candidate Abelardo de la Espriella and leftist senator Iván Cepeda failed to secure an outright majority in Sunday's first round of voting.

With 99.97% of ballots counted, Espriella secured 43.7% of the vote with approximately 10.3 million votes, while Cepeda received 40.9% with about 9.6 million votes. The narrow margin between the candidates sets up a competitive runoff election scheduled for three weeks from now.

Espriella, a lawyer who has expressed admiration for Donald Trump, emerged as an outsider candidate who rose rapidly in polling leading up to the election. His strong first-round performance represents what observers describe as part of a broader right-wing trend across Latin America.

Cepeda, a philosopher and human rights activist, has served as a senator since 2014 and received backing from outgoing leftist president Gustavo Petro. The senator's campaign focused on continuing progressive policies implemented during Petro's administration.

Following the results, President Petro raised concerns about the electoral process, though he did not specify particular allegations. The election results showed his preferred successor heading to the runoff despite earlier polling that had suggested different outcomes.

The runoff election will determine Colombia's next president, with the winner set to take office and lead the South American nation of approximately 50 million people for the next presidential term.