Colombia has accused Venezuela of moving troops to their common border with technical assistance from Iran and Russia, Reuters reported.

Citing intelligence sources during an anti-drugs conference in Colombia's Caribbean city of Cartagena on Thursday, Defense Minister Diego Molano said that the troop movements took place near Colombia's Arauca province, which is the scene of violent drug war between guerrillas of the National Liberation Army (ELN) and FARC dissidents.

Molano called the deployment "foreign interference", saying, "We know that men and units of the FANB (the Spanish acronym for National Bolivarian Armed Forces of Venezuela) have been mobilized towards the border with technical assistance from Russia...and Iran”.

Colombia's human rights ombudsman has reported that clashes between the armed groups for control of the drugs trade in Arauca has left 66 dead and 1,200 displaced in January alone.

The Colombian government says Venezuelan President Nicolas Maduro is sheltering both FARC dissidents and the ELN, an accusation that has been repeatedly denied.

Venezuelan Defense Minister Vladimir Padrino Lopez called the allegation by his counterpart "inappropriate statement".

He described Colombia as the country which “Bogota's oligarchy has converted into an appendix of the (United States) South Command in our America, into a location of US military bases”.

Iran and Venezuela have strengthened their cooperation in recent years and continue exchanging oil products despite US sanctions on both countries, without any visible action by Washington, which tries to engage with both.