Venezuela's acting President Nicolas Maduro urged US President Barack Obama on Sunday to halt an alleged plot to kill opposition leader Henrique Capriles ahead of the April 14 presidential vote.
Capriles, whom Chavez beat in October, is running in the upcoming election against Maduro, Chavez's handpicked successor.
Maduro told the private Televen station that the US-planned plot aims to "blame the government" for the attack and "create chaos in Venezuela," which was rocked earlier this month by the death of longtime president and US foe Hugo Chavez after a two-year battle with cancer.
He accused the CIA and the Pentagon, as well as former US diplomats Roger Noriega and Otto Reich, who also served as US ambassador to Venezuela, of planning the scheme.
Maduro also said opposition groups were involved, and vowed his government would provide "protection for all presidential candidates," and in particular Capriles.
But Capriles, the governor of Miranda state, took to Twitter to say Maduro would be to blame for "anything that happens."
Washington and Caracas have had strained diplomatic ties ever since Chavez first came to power in 1999. They have not had ambassadors in their respective capitals since 2010.
Venezuela has accused the United States on a number of occasions of being behind plots to overthrow or kill Chavez, and of trying to destabilize the government.