US agents arrested former head of the Bolivian anti-narcotics police Gen Rene Sanabria last week on charges of drug trafficking, which he denies.

Mr Morales said the affair did not mean that the police as a whole or the government had links to drug dealers.

President Morales expelled all the US agents working for the Drug Enforcement Administration (DEA) from Bolivia in 2008, saying they were aiding his opponents.

'Blackmail'

Since the arrest last week of Gen Sanabria by DEA agents in Panama, some opposition politicians have been calling for the return to Bolivia of the American agents to help the Andean country in its fight against drug trafficking.

But President Morales said the DEA was "an instrument the US uses to blackmail those countries who don't comply with imperialism and capitalism".

He said that even though Bolivia was only a small country, its government, armed forces and police would not bow to the DEA.

"The fight against drugs is driven by geopolitical interests," he said.

"And when a policeman is tainted, that's the problem of that policeman, but they're using him to implicate the government," he added referring to the arrest of Gen Sanabria.

Gen Sanabria is facing charges in a Miami court of trying to smuggle 100kg of cocaine into the US and heading a drug-smuggling gang made up of a dozen Bolivian police officers.

He headed Bolivia's anti-narcotics operations from 2007 to 2009, and was in charge of an intelligence unit in the Bolivian interior ministry at the time of his arrest.

According to the United Nations 2010 World Drug report, Bolivia is the world's third largest producer of coca, the leaf from which cocaine is made.

In a report published on Thursday, US authorities accused Bolivia of "failing demonstrably" in its fight against the drugs trade.