The US and a group of Latin American countries say they have deep concern about statements and actions that cast doubt on the outcome of Colombia's election.
"We observe with deep concern the recent statements and actions that, without duly substantiated grounds, cast doubt on the integrity of the electoral process in the Republic of Colombia," a joint statement released by the State Department said. It did not cite any specific action or comment.
It was signed by the US, Argentina, Bolivia, Chile, Costa Rica, Dominican Republic, Ecuador, El Salvador, Guyana, Honduras, Panama, Paraguay and Trinidad and Tobago.
Colombian right-wing candidate Abelardo De La Espriella clinched a tight victory in last month's presidential election. US President Donald Trump had endorsed him.
Friday's joint statement came from the countries called the "Shield of the Americas," a Trump-created military alliance of right-wing leaders pledging to fight drug trafficking.
Trump had publicly feuded with Gustavo Petro, a former rebel and Colombia's first leftist president. Colombian leftist senator Ivan Cepeda conceded in the country's presidential race late last month.
Cepeda criticised what he cast as foreign interference by Trump in the race, said voters had been manipulated by content made with artificial intelligence and accused De La Espriella of a vote-buying operation, without providing evidence.
De La Espriella, who promised a crackdown on crime and an economic revival, also accused Cepeda of vote-buying, without providing evidence.
Trump himself had falsely claimed he won the 2020 US election that he lost to former President Joe Biden before returning to the White House last year after winning the 2024 election. His supporters stormed the US Capitol in an unsuccessful attempt to prevent Congress from certifying the results of the 2020 vote.
Trump has moved to increase US presence and influence in Latin America. He ordered the seizure of ousted Venezuelan leader Nicolas Maduro in a deadly raid and the US military has carried out multiple strikes on boats in the Caribbean that have killed dozens.
Rights advocates say such actions are illegal, imperial and amount to extra-judicial killings. Trump casts them as attempts to counter drug trafficking and illegal immigration.