BOGOTA, June 2 (Xinhua) -- Colombian President Gustavo Petro on Tuesday rejected U.S. President Donald Trump's public endorsement of a far-right candidate in Colombia's presidential election, urging Colombians not to become "slaves or a colony" of anyone.

"When one country interferes in the decisions of another, freedom ceases to exist," Petro said on X, calling on all Colombians to vote in a completely free environment.

Earlier on Tuesday, U.S. President Donald Trump congratulated Abelardo de la Espriella, an independent candidate associated with the far-right Defenders of the Homeland movement, on leading in the first-round vote, saying "it is my Honor to give Abelardo my Complete and Total Endorsement."

Colombia held the first round of its presidential election on Sunday. Preliminary results show Abelardo de la Espriella and Ivan Cepeda of the ruling left-wing Historic Pact coalition advanced to the presidential runoff after emerging as the top two candidates in the first-round vote.

Under Colombia's constitution, a president serves a single four-year term with no re-election. Petro is not on the ballot.

The runoff is scheduled for June 21, with the winner to be sworn in on Aug. 7. ■