By JUAN FORERO
 
BOGOTÁ, Colombia, April 14 - With relations between the United States and Venezuela already strained, Hugo Chávez, Venezuela's combative president, accused the United States on Tuesday of spreading chaos in Iraq and expressed support for Iraqis fighting American soldiers.

The State Department's top diplomat on Latin America responded Wednesday, saying Mr. Chavez's recent comments have made it difficult for Washington to maintain normal relations with Venezuela.

Mr. Chávez issued some of his most vitriolic comments before thousands of cheering supporters in a speech marking two years since his return to power after he was briefly ousted in a coup he says was engineered by the Bush administration.

He held the United States responsible for the violence in Iraq, saying the "blame for all the dead has a name: George W. Bush."

"From Latin America, from Venezuela, we send out our heart to our brothers, the Iraqi people and the Arab people in the Middle East who are fighting against the imperialist aggressor," Mr. Chávez said.

On Wednesday, Roger Noriega, the assistant secretary of state for Western Hemisphere affairs, said that "negative examples" from Mr. Chávez were mounting. He called for a "rigorous assessment" by the international community of Venezuela's respect for the law and human rights.

"We obviously want to maintain normal relations, but it is very difficult when the president continues in his very negative declarations and his irresponsible declarations about my country," Mr. Noriega told reporters in Washington.

Mr. Noriega also reiterated the Bush administration's call for Mr. Chávez's government to permit a referendum in Venezuela on whether to recall him from office, which is allowed by the country's Constitution.

Mr. Chávez, who was elected to office in 1998, has become increasingly antagonistic as Bush administration officials have pressed for a recall referendum on his rule.

On Monday, the electoral chamber of the Supreme Court ordered the electoral authorities to accept hundreds of thousands of signatures collected by the opposition to force a referendum. But the ruling is not likely to go into effect until disputes between the pro-opposition electoral chamber and the pro-Chávez constitutional chamber are resolved.

The opposition is hoping that the Supreme Court will order the National Electoral Council to validate the signatures it temporarily sidelined in March. Diplomats who monitored the signature gathering, which took place in December, said the ruling appeared to be excessively technical.

The dispute has intensified the conflict in Venezuela between opposition groups led by businessmen, political leaders and media owners, and Mr. Chávez, whose populist policies have alienated much of the middle and upper classes.

Though Mr. Chávez has frequently accused the United States of trying to oust him, citing American aid for political opposition groups, he was particularly forceful in his latest comments, accusing the White House of hatching the April 11, 2002, coup.

A State Department official on Wednesday denied any American role in the coup, which failed two days later when an uprising reinstated Mr. Chávez.

"Repeating baseless charges does not make them true," said the official, who spoke on the condition of anonymity. "This is clearly another attempt to divert attention away from the Venezuelan people's continued efforts to overcome political polarization."