Caracas - Venezuela's acting president urged US leader Barack Obama to stop what he called a plot by the Pentagon and the Central Intelligence Agency (CIA) to kill his opposition rival and trigger a coup before a 14 April election.
Nicolas Maduro said the plan was to blame his opponent's murder on the Opec nation's government and to "fill Venezuelans with hate" as they prepare to go to vote following the death of socialist leader Hugo Chavez.
Maduro first mentioned a plot against his rival, Henrique Capriles, last week, blaming it on former Bush administration officials Roger Noriega and Otto Reich. Both rejected the allegations as untrue, outrageous and defamatory.
"I call on President Obama - Roger Noriega, Otto Reich, officials at the Pentagon and at the CIA are behind a plan to assassinate the right-wing presidential candidate to create chaos," Maduro said in a TV interview broadcast on Sunday.
Maduro, who is Chavez's preferred successor, said the purpose of the plot was to set off a coup and that his information came from "a very good source".
During his 14 years in power, the charismatic but divisive Chavez, who died on 5 March after a two-year battle with cancer, often denounced US plots against him and his "revolution". Critics dismissed those claims as a smokescreen to keep voters focused on a sense of "imperialist" threat.
Death as a campaign tool
In kicking off the opposition's campaign in the provinces on Saturday, Capriles said Maduro would be to blame if anything happened to him.
Capriles, a 40-year-old centrist state governor who cites Brazil as his economic model for Venezuela, accuses Maduro of using his boss's death as a mawkish campaign tool ahead of the 14 April vote.
Maduro, aged 50, a former bus driver who is trumpeting his working-class roots like Chavez, has a lead over Capriles of more than 10 percentage points, according to two recent opinion polls. Both were conducted before Chavez's death.
Maduro has sought to emulate the late president's common touch and emotional bond with voters but has struggled - beyond copying Chavez's bombastic rhetoric against foes at home and abroad.
In Sunday's interview, recorded at the military museum where Chavez's body was carried in a sombre funeral procession on Friday after 10 days of mourning, Maduro said he had cried more when Chavez died than when his own parents passed away.
Later on Sunday, his campaign team plans to launch Maduro's official Twitter account in another move reminiscent of Chavez. Chavez's @chavezcandanga account had drawn more than 4 million followers before his death - making it the second most-followed presidential account after Obama's.
Largest oil reserves
The election campaign began in a particularly nasty atmosphere, with both sides accusing each other of dirty tricks, and Capriles and Maduro landing very personalised blows.
At stake in the election is not only the future of Chavez's leftist revolution but also the continuation of Venezuelan oil subsidies and other aid crucial to the economies of leftist allies around Latin America, from Cuba to Bolivia.
Venezuela boasts the world's largest oil reserves.