The American administration has officially designated the Gulf Clan, the nation's most dominant and formidable criminal group, as a terrorist entity.
This infamous drug-trafficking faction, with origins in far-right paramilitary forces, operates in at least 20 of Colombia's provinces.
It monopolizes key human and narcotics trafficking routes through the notorious Darién Gap and has clashed leftwing rebels for control of criminal networks along the shared border.
In recent years, the organization has sought to rebrand itself as a political movement, like other Colombian rebel groups.
This maneuver could grant it different conditions in any potential peace talks. However, it is not widely considered to have tangible political aims.
In a recent announcement, the US top diplomat described the Gulf Clan—which goes by the name the Gaitanist Self-Defense Forces of Colombia (AGC)—as a "violent and powerful criminal organisation."
He emphasized it has "thousands of members" and that its "primary source of income is cocaine trafficking, which it uses to fund its armed operations."
While other Colombian criminal groups have been listed as terrorist groups before, this decision is the initial under the current administration.
This government has already designated six cartels in Mexico and a pair in Venezuela.
The action is expected to heighten tensions between the US and Colombia's president, who has vocally criticized the US pressure campaign against Venezuela.
This encompasses lethal military strikes on vessels that have reportedly killed scores of people in coastal waters.
The two presidents have traded public barbs for weeks. After implying that any drug-producing country was a possible focus, the US president specifically mentioned Colombia, stating the Colombian leader "will face significant difficulties if he doesn't change course."
The Colombian president retorted by warning his US counterpart to "avoid provoking a strong response" with militaristic threats.
The US has cited its war on drugs to justify the maritime attacks it claims are transporting illicit cargo.
The Colombian president has labeled these attacks as "unlawful killing." Early on Tuesday, the US military stated it had carried out new strikes on three vessels near Colombia's Pacific coast, resulting in eight fatalities.
Other Colombian armed groups have been on the US terror list for a long time.
Some authorities in Colombia had believed the Gulf Clan might be weakened by the capture and extradition of its main leader to the US in 2022.
Instead, the group unleashed a campaign of terror, killing police officers and local leaders and keeping large swaths of the country hostage.
The Gulf Clan is now engaged in fragile talks with the government. It is seen as the main obstacle to the president's struggling "total peace" plan, which aims to end the country's multifaceted armed conflict.