Venezuelan President Hugo Chavez has said he is about to expel a US missionary group, New Tribes Mission.
Chavez announced the news to indigenous people in Apure state
The leftist leader said the missionaries were "imperialists" and he felt "ashamed" at their presence in indigenous areas of Venezuela.
He accused the Florida-based group of making unauthorised flights and setting up luxurious camps amid poverty.
New Tribes, which preaches to non-Christian indigenous peoples, said it had no immediate comment.
It is one of Latin America's biggest missionary organisations and has 3,200 workers and operates in 17 countries, with operations in West Africa and South-East Asia too.
Caracas has suggested that American evangelicals are part of a broader conspiracy in Washington to topple a president whose regional influence is growing thanks to massive oil revenues, the BBC's Simon Watts writes.
US officials clearly do not like Mr Chavez much but they strongly deny any plot and it is also hard to tell how genuinely the Venezuelan president believes what he says.
Like his friend Fidel Castro, our analyst adds, Mr Chavez thrives on conflict and finds it politically useful to portray himself as a victim of US aggression.
"The New Tribes are leaving Venezuela," Mr Chavez said at a ceremony to present land titles and farming equipment to members of Venezuela's indigenous population.
"This is an irreversible decision that I have made. We don't want the New Tribes here. Enough colonialism!"
He added that he had yet to sign the expulsion order and was giving New Tribes time to "gather their stuff".
New Tribes, he said, flew in and out of the country without proper permission from the authorities.
"These violations of our national sovereignty have to stop," Mr Chavez said.
The president, long at loggerheads with the US over his leftist views, accused the group of building expensive luxury camps for themselves alongside poverty-stricken villages.
Mr Chavez said Venezuela was finally "doing justice" by its indigenous peoples by granting them land.
One indigenous deputy, Noheli Pocaterra, said Mr Chavez's government had made progress on indigenous issues but more needed to be done.