GM says its due process rights were violated and it will take legal steps to fight the seizure.
The automaker said the seizure showed a "total disregard" of its legal rights.
This isn't the first time Venezuela's government has seized foreign-owned factories.
A Venezuelan judge ordered the seizure of the plant, accounts and other assets in an action that GM classified as an "illegal judicial seizure".
GM's subsidiary in the country - General Motors Venezolana - has operated in Venezuela for almost 70 years.
GM responded says it stands by its original description of events.
General Motors' announcement comes as Venezuela's opposition looks to keep up pressure on President Nicolas Maduro, taking to the streets again Thursday a day after the biggest anti-government demonstrations in years.
The move has energized Venezuela's fractious opposition, which had been struggling to channel growing disgust with Maduro over widespread food shortages, triple-digit inflation and rampant crime. The price of consumer goods has skyrocketed. At least four people have been killed in the protests. Perhaps more important to his overall strategy will be the distribution of seized civilian arms to the government-loyal "militias" on which Maduro is relying on as the protests escalate.
The three deaths bring to eight the number of people killed since protests began three weeks ago over the Supreme Court's decision to strip the opposition-controlled Congress of its last remaining powers, a move that was later reversed amid a storm of global criticism. The Supreme Court also blocked all reforms from opposition lawmakers.
G.M. had asked the government to help the company retake control of the plant, he said, but instead, the government took over the facility itself.
Maduro and his predecessor, the late Hugo Chavez, have seized the assets of foreign companies on several occasions, including a "temporary" takeover of two plants owned by USA company Clorox in 2014.
The plant employees tell NPR they believe dealers took over the plant out of frustration that the facility has not been producing cars recently.
Coca-Cola has recorded multiple losses in recent years from its Venezuela business, and it temporarily halted production there last year due to a lack of sugar supply in the country.
GM has about 2,700 workers in the troubled country, where it's been the market leader for over 35 years.
GM announced the plant confiscation Thursday, saying its plant in Valencia "was unexpectedly taken by the public authorities, preventing normal operations".
"As a outcome, GMV announces the immediate cessation of its operations in the country, and ensures (as far as the authorities permit) payment of the employees' separation benefits arising from the termination of the employment relationships due to causes beyond the parties' control", the statement reads. Union leaders at the plant said in February that GM had not assembled any new vehicles in Venezuela since 2015 and was limiting production to replacement parts.