"The Russian government approved financing of 2.2 billion (U.S. dollars) for the cost of the weapons," President Hugo Chavez said in his weekly radio and television broadcast.

"Thanks to the support of the Russian President (Dmitry Medvedev) and the Prime Minister (Vladimir Putin), the purchase of arms aimed at boosting our defensive capacity has became viable."

Chavez described some of the weapons in the new arsenal, including 92 Soviet-era T-72 main battle tanks that his military will receive "in order to modernize our fleet of armored vehicles."

Chavez has long expressed a desire to improve his nation's military with Moscow's help, and the substantial deal comes amid rising tensions between Caracas and Bogota over Colombia's decision to allow the United States access to several military bases on its territory.

The firebrand leftist has repeatedly criticized the United States but has insisted that the latest purchase was not directed against any other country.

In addition to the tanks, Chavez announced his government will take delivery of 300mm Smerch multiple launch rocket systems.

"We have signed the contract already for this equipment," the president said. "With these rockets it is going to be very difficult for them to come and bomb us. If that happens, they should know that we will soon have these systems installed, (and) for an enemy that appears on the horizon, there it goes."

The arsenal will also include vehicle-mounted Russian Antey 2500 surface-to-air missile systems that target incoming tactical missiles.

Chavez insisted his country's massive oil and gas reserves warranted the protection afforded by a military buildup.

"We have the largest petroleum reserves in the world. The empire has set its sights on them," Chavez said. Latin America's loudest U.S. critic often describes the United States as an empire.

"We have the right to take the minimum necessary steps to guarantee to the public our national security and our (energy) treasure."

The growing presence of Chinese, Russian and Spanish firms in the vast Orinoco oil belt, fields believed to be among the largest in the world, provide "a new geopolitical dimension as we establish the parameters of military and our sovereignty," he said.

In recent years Venezuela has signed over four billion dollars worth of arms contracts with Russia, and last November its navy held joint exercises with Russian warships in the Caribbean, traditionally seen as a U.S. domain.