President Hugo Chavez has said he will not tolerate the presence of Colombian guerrillas in Venezuelan territory, adding that he is confident Colombia's government would in turn capture any opponents conspiring against his own.
"We are not going to allow the presence of any armed group," including rebels, paramilitary fighters and drug traffickers in Venezuelan territory," Mr Chavez said before meeting with former Brazilian President Luiz Inacio Lula da Silva.
"We have fulfilled our obligations."
The socialist leader's comments came a day after Colombian president Juan Manuel Santos announced that a top commander of the Revolutionary Armed Forces of Colombia, or Farc, was captured across the border in Venezuela.
Venezuelan security forces captured Guillermo Torres, better known by his alias Julian Conrado, and later contacted Colombian authorities after identifying the rebel leader, Mr Chavez said.
Venezuela announced in a statement that Torres would soon be extradited to Colombia.
Venezuela has for years been a refuge for Colombia's leftist guerrillas. But Mr Chavez and Mr Santos have forged a pragmatic friendship despite their deep ideological differences and promised to work together to prevent Farc rebels from seeking refuge in Venezuela.
Mr Chavez suggested the arrest of Torres indicates that collaboration between the South American neighbours is producing positive results, and he said he expects the co-operation to continue.
Torres is the most senior Farc commander captured since 2004. He is on the Farc's general staff, second in the command chain after the rebels' seven-member secretariat, and is also renowned for composing and performing rebel anthems during failed 1999-2002 peace dialogues.
The United States had offered a 2.5 million US dollar reward for the Farc leader's capture.