The group works with indigenous peoples
Venezuela has given a US missionary group 90 days to leave the country.
President Hugo Chavez had earlier accused New Tribes of providing sensitive information to the CIA.
The Florida-based missionaries deny the charge, and say they have been working for the good of Venezuela's indigenous peoples for decades.
They had hoped to persuade officials to allow them to stay, but an expulsion order has now been published in the country's official gazette.
Last month, Mr Chavez announced he would expel the group, accusing it of making unauthorised flights and setting up luxurious camps amid poverty.
"These are real imperialist infiltrations," he said.
Accusations that the group was working with the CIA were rejected by New Tribes, which preaches to non-Christian indigenous communities.
"When you consider the people that we're with, there really isn't any sense of strategic information they would have," spokeswoman Nita Zelenak said in October.
Mr Chavez has been at loggerheads with the US for some time.
He has in the past accused the US of plotting to assassinate him and suspended co-operation with the US Drug Enforcement Agency after accusing its officials of spying.
Washington strongly denies any plot.