Venezuela has taken delivery of three Russian-built military helicopters - the first of a total of 15 it has so far ordered from Moscow.
Chavez is looking to boost Venezuela's armed forces
President Hugo Chavez said they would help to protect Venezuela if the US ever mounted an invasion.
Mr Chavez also repeated that he was ready to buy Russian fighter jets.
Washington has dismissed claims of a possible invasion as ridiculous and says Mr Chavez's military purchases pose a threat to regional stability.
A crowd of Russian and Venezuelan generals and diplomats was treated to an air show, displaying the strengths of the Russian-built helicopters.
A group of around 20 parachutists jumped in formation out of the olive green MI-17 helicopters during Monday's ceremony.
President Chavez said Venezuela's latest purchases could be used to transport parachute troops quickly into combat.
This would be ideal for a war of resistance, Mr Chavez said, a reference to his often repeated concerns that the US may want to invade Venezuela to seize its oil reserves.
Army Commander Gen Raul Baduel said Venezuela planned to buy a total of 33 helicopters from Russia.
Balance of power
Venezuela has also agreed to buy a total of 100,000 Kalashnikov assault rifles from Russia.
Russian Kalashnikovs will replace Venezuela's ageing assault rifles
Mr Chavez also repeated his accusation that the US had blocked a deal to buy training aircraft from the Brazilian manufacturer, Embraer, because the Brazilian planes contained protected American technology.
"Nothing and nobody will stop us from making our country's armed forces stronger," he said, while stressing that Venezuela was not preparing to invade anybody.
The BBC's Greg Morsbach in Caracas says Mr Chavez's words may do little to dispel fears in Washington that Venezuela is stepping up its arms expenditure and is upsetting the balance of power in Latin America.