Colombia says an alleged Venezuelan drugs kingpin arrested earlier this year will be extradited to Venezuela, rather than the US.
President Juan Manuel Santos said he had given his word to President Hugo Chavez of Venezuela that the suspect, Walid Makled, would be sent home.
Mr Makled is accused of smuggling tons of cocaine into the US. He alleges he was supported by Venezuelan officials.
The decision is a sign of improving ties between Colombia and Venezuela.
President Chavez had expressed concern that a trial in the US might be used to wrongly implicate his government in drugs trafficking.
Walid Makled was a successful businessman in Venezuela whose family owned an airline, a transport company and several warehouses.
He went into hiding in 2008 after his brothers were arrested after large quantities of cocaine were found at a family ranch, and was himself arrested in Colombia last August.
The US authorities say he is one of the most wanted drug traffickers in the world.
Also known as "the Turk" or "the Arab", he is accused of running a "vast international narcotics trafficking organisation" which smuggled tons of cocaine into the US in planes flying from airstrips he controlled.
In Venezuela, he is also wanted for the murder of a journalist and a Colombian drug lord.
He has denied the charges, saying the authorities framed him in order to seize his businesses.
Mr Makled's case became a political issue in Venezuela when he alleged in media interviews from prison that he paid millions of dollars to senior officials in the Venezuelan government.
"If I am a drug trafficker, then so are all these people from high government", he said.
Venezuelan officials have dismissed the claims, saying Mr Makled would say anything to avoid the prosecution.
President Chavez has also accused the US of offering Mr Makled improved conditions in return for implicating his government in drug trafficking.
President Santos's decision is the latest sign of improving relations between Colombia and Venezuela, which were severely strained under his predecessor, Alvaro Uribe.
"I gave my word to President Chavez that once the judicial processes are completed we would hand this individual over to Venezuelan authorities," he said.
"When we captured him, the extradition request from Venezuela came before the extradition request from the US."