"If they kill me, there will be a really guilty party on this planet whose name is the President of the United States George Bush," Chavez said on Sunday during his weekly radio programme Hello, Mr President.
"If, by the hand of the devil, those perverse plans succeed... forget about Venezuelan oil, Mr Bush," he said.
Chavez said he was convinced that Washington was "sketching out the assassination plans" before his Bolivarian Revolution advances in Venezuela and Latin America.
Chavez revealed a week ago that Cuban President Fidel Castro had warned him of a US assassination plot.
"Now, I am going to say it. Neither Fidel Castro nor I talk nonsense."
US Secretary of State Condoleezza Rice recently called Chavez "a negative force" in Latin America, and the State Department backed Colombia in a recent dispute between the Caribbean neighbours over the arrest of a Colombian rebel in Caracas by Colombian officials without Venezuela's knowledge or consent.
"If something happens to me, I blame the president of the United States," Chavez said.
"If they kill me, there will be a really guilty party on this planet whose name is the President of the United States George Bush"
"I will not hide. I am going to be in the streets with you. I entrust myself to God, but I know that I have been condemned to die," Chavez said.
"Each second of my life I will spend in the struggle and God's will be done," he said.
Castro said on 12 February: "If Chavez is assassinated, the blame will fall on Bush.
"I say that as someone who has survived hundreds of the empire's [assassination] plans," he said.
Chavez also recently accused the US of being involved in an April 2002 coup, which removed him from power but only for two days.
Venezuela is the only Latin American member of the Organisation of the Petroleum Producing Countries or Opec, and sells about 1.5 million barrels daily to the US.