President Hugo Chavez has said ties may be nearing breaking point
Colombia has accused Venezuelan President Hugo Chavez of meddling in its internal affairs as tension rises between the two South American states.
The accusation was made in a formal complaint lodged at the regional body, the Organisation of American States.
Ties have been strained over a planned deal to allow the US more access to Colombian military bases.
Latin American leaders are set to gather in Argentina on Friday to discuss the issue.
The Colombian government made its formal protest at the OAS after Mr Chavez described Colombia as a "narco-state" and ordered an investigation into Colombian companies operating in Venezuela.
Colombia also voiced anger at Mr Chavez's calls to his supporters to reach out to left-leaning Colombians in a bid to recreate Gran Colombia, a state that comprised both countries, Ecuador and Panama in the early 19th Century.
"Every state should have the regime it wants and the rest of the states should respect that condition," said Colombia's ambassador to the OAS Luis Hoyos, as he attacked what he called Mr Chavez's "interventionist" plan.
Share 2,200km (1,375 mile) border
Much common history, including Gran Colombia
Trade in 2008 about $7bn
"We hope that Mr President Hugo Rafael Chavez Frias uses his abilities and uses his talents to build collectively in the continent without sowing more hatred, respecting differences and not meddling in Colombia's internal affairs."
This week, Mr Chavez indicated that relations with Colombia, already frozen, could be heading for a rupture.
He said he would continue to speak out against the planned deal between Colombia and the US to allow the American military to use several bases on Colombian territory, a move he has characterised as a near declaration of war.
"It is the peak of cynicism, they (Colombia) who are going to install seven Yankee bases there, giving over the sacred territory of Colombia to imperial expansionism, now accuse me, accuse us of expansionism," Mr Chavez said.
Mr Chavez has already taken a number of steps against Colombia, including ending access to subsidised fuel and seeking to curb Colombian imports.
Colombia denies that the deal with the US is a threat to the region, saying it is designed to help its own forces tackle drug-trafficking and insurgents more effectively.
US Secretary of State Hillary Clinton has also sought to reassure Latin American nations about the planned accord.
"It does provide the United States access to Colombian bases but command and control, administration and security will be Colombia's responsibility," she said earlier this month.
Mr Chavez will seek to garner opposition to the plan at a Union of South American Nations (Unasur) summit in the Argentine ski resort of Bariloche on Friday.
His allies, Bolivia's Evo Morales and Ecuador's Rafael Correa, have voiced deep criticism of the accord.
Colombia, for its part, is calling for other issues, including other military deals in South America, to be discussed at the meeting.