The government of Venezuelan President Nicolas Maduro is increasingly providing shelter to Colombian rebel groups, a senior State Department official said in an interview, days after former FARC guerrillas announced a new offensive.
Former rebels from the Revolutionary Armed Forces of Colombia said they were abandoning a 2016 peace accord in a video released on Thursday that Colombian officials believe was likely filmed in Venezuela.
"We've known for some time that the FARC and ELN enjoy safe haven inside Venezuela," said the official, referring to the separate and smaller guerrilla group the National Liberation Army. "And it's even more clear now that they do so with the complicity of the Maduro regime."
Venezuela's information ministry did not immediately reply to a request for comment.
Maduro accuses the United States of seeking to overthrow him, and usually dismisses State Department accusations as politically-driven smear campaigns.
The rearmament of former FARC fighters threatens not only to stoke armed conflict in Colombia, but also to fuel violence in Venezuela's border region that for years has been a haven of smuggling and delinquency.
Colombian and US officials have for months voiced concerns about growing ELN activity in Venezuela, which shares a porous and isolated 2200km border with the neighbouring nation.
And Colombian authorities are concerned that the ELN is seeking new recruits among the flood of Venezuelans who are streaming across the border to escape the country's economic crisis. The presence of Colombian armed groups in Venezuela is further complicated by widespread access to guns in the troubled country, which suffers one of the world's highest rates of homicide.
"You have literally hundreds of thousands of military weapons that have gone missing from the Venezuelan armed forces," the official said.
Former rebel commanders Ivan Marquez and Jesus Santrich, in a video they said was filmed in Colombia's Amazon, accused Colombian President Ivan Duque's government of violating the peace accord and said the fighters would seek an alliance with the ELN.
Maduro in July had said Marquez and Santrich, whose location at the time was not known, were welcome in Venezuela.
The office of Opposition leader Juan Guaido, who has been recognised by more than 50 countries as Venezuela's legitimate leader, on Friday said Guaido's envoy to Washington had met with US authorities to warn that the FARC could regroup with Maduro's support.
"Unfortunately, these warnings have become a reality," Guaido's office said in statement.
Venezuela's foreign ministry on Friday blamed the rearmament on Duque's failure to follow through on the peace accords.
Maduro later tweeted that his government was committed to promoting peace in Colombia and would advance efforts to reestablish conversations between the two sides. Neither mentioned the issue of rebel presence in Venezuelan territory.