A Mexican plane forced down and destroyed in Venezuelan territory earlier in the week was full of cocaine, President Nicolas Maduro said.
Maduro said he was surprised that Mexico had asked for an explanation of the November 4 incident through diplomatic channels.
"That was a plane that we found full of drugs," said Maduro yesterday, speaking during his weekly radio and television nationally broadcast address.
He said that he told Foreign Minister Elias Jaua "to give all the necessary explanations" to Mexico, but should "try to make the Mexican president know that he is standing up for an airplane that was full of cocaine."
On Monday Venezuelan air force warplanes forced a small executive jet with a Mexican license number to land in the state of Apure, near the border with Colombia.
Two days later Mexico formally asked Venezuela to explain the events "in strict accordance with international law."
"We are not going to accept that Venezuelan air space continues being used for narcotrafficking," Maduro said.
"Let it be known, we are not going to be stopped, neither with international campaigns nor blackmail," he said, in response to criticism over the drastic action.
A few hours after Maduro spoke, angry officials in Mexico City said they would summon Venezuela's ambassador tomorrow to demand an explanation.
Up to now Venezuela had not said that there were drugs aboard the plane, a statement from Mexico's foreign ministry read.
Venezuela did tell Mexico that the plane entered Venezuelan air space without authorisation, and that it was chased for 40 minutes, all the time ignoring radio warnings, the Mexican statement read.
The Venezuelans also said the plane landed on a remote landing strip and that there was no trace of the people aboard, the statement added.
Mexican officials said Friday that the seven people aboard the plane - two crew members and five passengers - flew from the central Mexican state of Queretaro under false identities.
Venezuela's air force on Monday released images of the plane fuselage still in flames.
Since May 2012, when a new airspace protection law came into effect, 30 airplanes have been brought down, according to Maduro. But this is the first time a plane registration number was released.
Venezuela's military say they conduct land, air and sea anti-narcotics operations along the border, where drug trafficking is rife.
