Chavez returned home by surprise Monday after spending two months in Cuba for cancer surgery and treatment.

The State Department said Tuesday the Venezuelan constitution should be respected if Chavez is deemed incapacitated, in which case new elections must be called.

The Venezuelan foreign ministry said those remarks were tantamount to "new and ugly interference by Washington in Venezuela's domestic affairs."

State Department spokeswoman Victoria Nuland had said that political transition in Venezuela is the business of Venezuelans, and if elections are in fact convened they should be free and fair, with open access to the media.

That kind of talk is right in line with the "destabilizing and corrupt right wing in Venezuela," the foreign ministry said.

"The only transition foreseen is the transition to Bolivarian socialism under the government" of Chavez, it added.

Venezuela and the United States have frosty relations. Caracas accuses Washington of 21st century imperialism and has irked the Americans by aligning itself with countries such as Iran, Cuba and Syria.