The United States has expelled two Venezuelan diplomats in retaliation for Venezuela's expulsion of two American military attaches last week.
U.S. officials say junior diplomats Orlando Jose Montanez Olivares and Victor Camacaro Mata already have left the United States.
Hours before the death of President Hugo Chavez last week, Venezuela ordered two U.S. Air Force attaches out of the country, accusing them of plotting to destabilize the country. The State Department calls their expulsions "unjust."
In Venezuela Monday, thousands of supporters cheered and cried as acting President Nicolas Maduro formally registered as a candidate in the April 14 election to officially pick a Chavez successor.
Opposition candidate Henrique Capriles says Maduro is playing politics with President Chavez's body. Maduro calls his rival "miserable" and accuses him of trying to stir up violence.
President Chavez, a strong socialist, died last week of cancer at age 58. Maduro accuses those he calls Venezuela's enemies, including the United States, of infecting the president. Washington calls the accusation "absurd."
State Department spokeswoman Victoria Nuland said Monday the United States hopes for better relations with a post-Chavez Venezuela, especially in fighting drugs and terrorism. But she said it is going to need a change in tone from Carcacas.