The king of Spain told Venezuelan President Hugo Chavez to "shut up" Saturday during a heated exchange that soured the end of a summit of leaders from Latin America, Spain and Portugal.

Chavez, who called President Bush the "devil" on the floor of the United Nations last year, triggered the exchange by repeatedly referring to former Spanish Prime Minister Jose Maria Aznar as a "fascist."

Aznar, a conservative who was an ally of Bush as prime minister, "is a fascist," Chavez said in a speech at the Ibero-American summit in Santiago, Chile. "Fascists are not human. A snake is more human."

Spain's current socialist prime minister, Jose Luis Rodriguez Zapatero, responded during his own allotted time by urging Chavez to be more diplomatic in his words and respect other leaders despite political differences.

The phrase used by the king, "¿Por qué no te callas?," is one that a parent might use on a disobedient child. Watch the exchange here: