Venezuela's foreign minister said Thursday he had decided to "suspend the activities" of the UN rights office in the country and ordered its staff to leave within 72 hours.
The move comes two days after the United Nations agency expressed "deep concern" over the detention of prominent rights activist Rocio San Miguel and called for her "immediate release."
In a statement on X, the office said the detention was a possible "enforced disappearance".
San Miguel, 57, was arrested last Friday in the immigration area of an airport in Caracas, sparking an international outcry.
Prosecutors have accused her of taking part in the latest alleged plot to assassinate President Nicolas Maduro, which the government has said was backed by the United States.
Foreign Minister Yvan Gil said the UN rights office had taken on an "inappropriate role" and had become "the private law firm of the coup plotters and terrorists who permanently conspire against the country."
He said the decision would remain in place until the agency "publicly rectify, before the international community, their colonialist, abusive and violating attitude of the United Nations Charter."
The United Nations Human Rights Office has been present in Venezuela since 2019.
The detention of San Miguel comes in a crunch election year that has already seen Maduro block his main opposition rival, prompting the United States to threaten to reimpose recently eased oil sanctions.
She was arrested alongside several family members who have since been released on bail.
However, her ex-husband, a retired soldier, was also arrested and is being charged with allegedly revealing "political and military secrets."
The detentions come after Venezuelan authorities in January said they had uncovered five plots to assassinate Maduro, implicating rights activists, journalists and soldiers.
Maduro frequently denounces plans to overthrow him, usually with the alleged involvement of the United States and the opposition.
San Miguel is the founder of an NGO called Citizen Control, which investigates security and military issues, such as the number of citizens killed or abused by security forces.
She has detailed military involvement in illegal mining operations, and a recent femicide in the army.
International rights groups see in the arrests a coordinated plan to silence government critics and perceived opponents.
An independent fact-finding mission to Venezuela set up by the UN Human Rights Council -- a different body made up of 47 member states -- condemned the "intensifying" repression of opponents in the country.
"These are not isolated incidents, but rather a series of events that appear to be part of a coordinated plan to silence critics and perceived opponents," said Marta Valinas, chairwoman of the mission, in a statement Tuesday.
The wave of criticism angered Caracas, and Attorney General Tarek William Saab who slammed a "ferocious campaign from abroad against the justice system and the Venezuelan state."
