Venezuela's Congress has approved the president's request for expanded powers, effectively paving the way for him to rule by decree.
Nicolas Maduro's request to enact laws for up to six months without consulting Congress is expected to gain final approval on Sunday and is intended, he says, to protect the country from US "imperialism".
He made the move after Washington imposed sanctions on Monday on several top Venezuelan officials accused of human rights violations.
Maduro said the legislation would allow him to issue decrees for the "protection against meddling by other states in the internal affairs of the republic, militaristic actions or any external or internal activity that aims to break the peace".
Analysts and non-governmental organisations said Maduro could seize on the special powers to curb individual rights, invoking the spectre of an external threat to justify his request.
"Using the external enemy, which is imperialism, the government takes advantage to build a more repressive legal framework," Edgard Gutierrez, coordinator of the Venebarometro polling firm, told the AFP news agency.
Rocio San Miguel, head of the Control Ciudadano NGO specialising in security issues, said the legislation would "be an instrument against the internal enemy ... to undermine human rights".
The US State Department denied that Washington was promoting "instability" or seeking to undermine Maduro's administration, with spokeswoman Jen Psaki saying "the goal of the sanctions is to persuade the government of Venezuela to change their behavior".
Obama called oil-rich Venezuela "an extraordinary threat to the national security" of the United States. The two nations have not exchanged ambassadors since 2010.
Despite the rift, Venezuela continues to be a major oil exporter to the US, shipping almost one million barrels per day up north.