President Hugo Chavez dismissed Washington's concerns that Venezuela's democracy is under threat, saying a "dictatorship" led by President Bush poses a true threat to democracy around the world.

Condemning the war in Iraq, the Venezuelan leader said that Bush and John Negroponte, a former director of national intelligence who is designated for the No. 2 position in the State Department, should be tried for "war crimes" committed by the U.S. military across the globe.

"The two of them are criminals. They should be tried and thrown in prison for the rest of their days," Chavez told a news conference.

"If he had any dignity, the president of the United States would quit. The U.S. president doesn't have the political or moral capacity to govern," he added.

Chavez was responding to comments made on Wednesday by Bush, who said he was concerned about Venezuela's democracy.

"I am concerned about the undermining of democratic institutions. And we're working to help prevent that from happening," Bush said in an interview with FOX News.

Relations between Caracas and Washington have been tense recently, with U.S. officials accusing Chavez — a close ally of Cuban leader Fidel Castro — of becoming increasingly authoritarian and Chavez accusing U.S. officials of scheming against his left-leaning government.

Last week, Chavez threatened to expel U.S. Ambassador William Brownfield for "meddling" in Venezuela's domestic affairs. Brownfield has called for improved relations between the two countries, but said he's ready to leave if the Chavez administration decides to expel him.

Chavez fiercely denied that his initiative to accelerate changes in broad areas of Venezuelan society through presidential decree, which was approved by the pro-Chavez Congress on Wednesday, would endanger his country's democracy.

"The people gave me the power I have, and it's within the framework of a constitution," Chavez said.

Critics have called the measure giving Chavez sweeping powers to legislate as a move toward dictatorship.

The law gives Chavez, who is beginning a fresh six-year term, more power than he has ever had in eight years as president, and he plans to use it during the next 18 months to transform this oil-rich South American nation.

Chavez, a former army lieutenant colonel who was re-elected with 63 percent of the vote in December, also announced that his government would nationalize oil projects in Venezuela's Orinoco River basin by May 1.

Any foreign oil company that resists the nationalization, under which Venezuela's state oil company Petroleos de Venezuela SA would take a stake of "no less 60 percent," can leave, Chavez said.

The Venezuelan president said the private companies affected — British Petroleum PLC, Exxon Mobil Corp., Chevron Corp., ConocoPhillips Co., Total SA and Statoil ASA — would be given the option to stay on as minority partners in petroleum-rich region.

"I'm sure that they're going to accept this because we are going to continue being partners. Now, if they aren't in agreement, they are totally free to leave," he said.

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