Story highlights Venezuelan authorities claim Fox was "promoting violence"

Fox says Sunday's vote weakened Venezuelan leadership

(CNN) Venezuelan authorities have declared former Mexican President Vicente Fox a "persona non grata" and banned him from ever returning to the country.

Fox was in Venezuela, along with other former Latin American presidents, to act as an observer in Sunday's non-binding referendum called by the opposition on government plans to reform the constitution.

El Sr. Fox vino pagado a Venezuela para promover la violencia y la intervención de potencias extranjeras. (3/6). — Samuel Moncada (@SMoncada_VEN) July 17, 2017

In a series of tweets, the Venezuelan foreign minister, Samuel Moncada, says Fox abused the goodwill of the Venezuelan people and came to the country to "promote violence and the intervention by foreign world powers," a claim that Fox rejected.

Fox greets voters at a Caracas polling station during the referendum Sunday.

"As a preventative measure to protect our people, Señor Fox will never again be able to come back to Venezuela," Moncada wrote.

Fox told CNN he wasn't surprised that President Nicolas Maduro took this action against him. Maduro, he said, is imposing his will "with a stick in his hand -- with the guns and ammunition."

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