BOGOTA: The United States said on Monday (Sep 15) it has decertified Colombia as an ally in the fight against drugs, a decision that could cost Bogota hundreds of millions of dollars in US military support.

After decades of close alliance in the so-called war on drugs, US President Donald Trump denounced his Colombian counterpart Gustavo Petro for not only failing to curb cocaine production, but overseeing its surge to "all-time records", according to a signed determination the White House sent to Congress on Monday.

"Under President Petro's leadership, coca cultivation and cocaine production have reached record highs while Colombia's government failed to meet even its own vastly reduced coca eradication goals, undermining years of mutually beneficial cooperation between our two countries against narco-terrorists," Trump wrote.

The Trump administration has repeatedly pressured Petro, the first leftist elected to lead Colombia, and voiced hope for a shift after elections next year.

"Colombia has been a great partner historically. Unfortunately, they have a president now that, in addition to being erratic, has not been a very good partner when it comes to taking on the drug cartels," Secretary of State Marco Rubio, a sworn enemy of leftist leaders in Latin America, said on a visit to Israel.

"I think we have willing partners, if it was up to the military, the police. We've been working with them for decades," Rubio told reporters, voicing hope that Colombia could be recertified in the future.

Washington has conducted assessments annually since 1986 on the anti-narcotics efforts of some 20 drug-producing and distributing countries.

In the case of Colombia, the world's largest cocaine producer, US assistance for anti-narcotics efforts reached some US$380 million a year, a figure which is now in jeopardy.

In a meeting with his cabinet, Petro confirmed the change, saying "the United States is decertifying us after dozens of deaths of police officers and soldiers" in the fight against drug cartels and leftist guerrillas funded by drug trafficking.

US decertifies Colombia as ally in drugs fight