The Venezuelan parliament on Tuesday rejected a decree granting special powers to socialist President Nicolas Maduro and the military, as the country's political and economic crisis deepens.
The opposition majority in the legislature accused Maduro of preparing for a dictatorship.
Deputy Enrique Marquez accused Maduro of having "totalitarian tendencies" and said the decree would have annulled the constitution.
Maduro earlier Tuesday accused the United States of plotting an invasion of the South American country, which is politically divided and suffering from a shattered economy that the president himself has described as catastrophic.
After last week's suspension of neighbouring Brazil's left-wing President Dilma Rousseff in an impeachment proceeding, which Maduro described as a coup, the threats against Venezuela have only increased, he said.
The epicentre of the plot against his government is in Washington, Maduro said at a news conference. He said that the US military had flown a spy plane last week over Venezuela.
US State Department spokesman John Kirby said he had no information about the supposed flight.
"We continue to stand with the international community in expressing our concerns about the difficult conditions the Venezuelan people are experiencing," Kirby said, noting worsening shortages of food, electricity, basic consumer goods and medical supplies, which have been rationed since January.
The US believes the solution to Venezuela's challenges requires the inclusion of all interested parties, he added.
Maduro said Tuesday that an initial plan "to push Venezuela into a conflict situation with the help of external agents and internal factors" had failed. Instead, excuses were being sought "for an invasion."
US ambassadors around the world have been assigned "to lobby against us and inflict damage on us," Maduro alleged.
His statements came as Venezuela's opposition, which won a majority in December in the unicameral National Assembly, tries to force a recall referendum to oust him. Election authorities last week rejected a petition with 1.8 million signatures.
Caracas saw major pro- and anti-government rallies on the weekend.
Venezuela, which is heavily dependent on petroleum exports, has seen its economy collapse in part due to sharply lower oil prices. Power outages have become widespread, and many government offices have been reduced to opening two days a week in an attempt to save electricity.
Last week, Maduro extended an economic state of emergency by 60 days, threatened to seize factories that halt production and ridiculed managerial complaints about shortages of raw materials.