About 80,000 troops were due to take part in the massive display of weaponry, as Caracas shows off its Chinese amphibian weapons, Russian-built missiles and other military hardware.
The exercises will last 10 days and will enlist the participation of 20,000 civilians, in addition to the troops, officials said.
The manuevers come at a time of heightened tensions with the United States, which has clashed repeatedly with the leftist-led South American country over the years.
After Obama made the move, which targeted senior Venezuelan officials for cracking down on the opposition, Caracas angrily recalled its envoy to Washington and ramped up its military preparedness.
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The country's defense minister, General Vladimir Padrino Lopez, said today that the maneuvers, many of which were to be held in the south of Caracas, were meant to prepare soldiers for "their mission, their goal, and with the will to be victorious."
Military officials said they will also test the nation's air defenses and will ensure that its anti-aircraft systems are ready to be deployed if needed.
President Nicolas Maduro has accused Washington of backing an alleged opposition plot to overthrow him. He is seeking extraordinary powers from the legislature that would allow him to rule by decree.
Maduro's popularity has sunk in the past year amid an economic crisis, galloping inflation and huge lines outside supermarkets plagued by drastic food shortages.
Communist Cuba rallied behind Maduro this week, pledging "unconditional support" to Caracas. Another ally, Ecuador's leftist President Rafael Correa, denounced the US sanctions as "grotesque" and a "sick joke.