Venezuelan President Hugo Chavez has vowed to defend Bolivia's government if there is an attempt to overthrow President Evo Morales.
Mr Chavez recently called President Bush "the devil"
Mr Chavez said: "Venezuela will not keep its arms crossed if the Bolivian government and people are attacked from outside or within."
Mr Chavez has recently accused Washington of plotting to topple his close ally in Bolivia.
Officials in Washington have denied such allegations.
In a televised speech, Mr Chavez said a US-backed plan was being implemented to impede Mr Morales' cabinet from governing effectively, so that his removal could later be justified.
Mr Chavez said Caracas would "do whatever it can so that the [next] government lasts as long" as that of Pedro Carmona, referring to a short-lived coup attempt against him in 2002.
He also warned that Venezuela would not recognise "any government that emerges through an insurrection".
Mr Chavez's comments come days after a military co-operation agreement was announced between Venezuela and Bolivia.
The deal has been criticised by Bolivian opposition representatives, who have raised concerns over the intervention of Venezuela in Bolivia's internal affairs.