Spain's King Juan Carlos told Venezuelan President Hugo Chavez to "shut up" during a tense exchange Saturday at the close of the 17th annual Ibero-American Summit in Santiago, Chile.

The leftist Venezuelan leader was interrupting a speech being given by Spanish Prime Minister Jose Luis Rodriguez Zapatero, when the king tried to silence him.

Mr. Zapatero had been criticizing Mr. Chavez for calling former Spanish Prime Minister Jose Maria Aznar a fascist.

After the exchange the Venezuelan leader argued that he was not being offensive by telling the truth, and said he reserved the right to respond to any aggression.

The three-day summit brought together 22 leaders of Spanish and Portuguese-speaking nations in Latin America, as well as Spain, Portugal and Andorra on Europe's Iberian peninsula.

On Friday, Mr. Chavez proposed a regional oil alliance for Latin America at the 17th annual Ibero-American Summit. 
He said an alliance would allow countries to share in the region's growing oil wealth, and allow oil-producing nations to sell it to neighboring countries at a lower price.

Also Friday, a meeting between the presidents of Uruguay and Argentina was marred after Montevideo approved a permit for a Finnish company to operate a paper mill on a river near the two countries shared border.

Argentine environmental activists say the paper mill will cause widespread water and air pollution.  Uruguay insists any contamination will be within normal international levels.

Some information for this report was provided by AFP, AP and Reuters.