President Hugo Chavez, who is settling back into governing this oil-rich but socially divided country, raised questions in an interview about a possible U.S. role in a coup last month that he says was an attempt on his life.

His return to the presidential palace three weeks ago has energized his mostly poor supporters, frightened the country's mostly wealthy opposition and left much of Latin America relieved by the resilience of democracy in a part of the world not known for that trait.

Yet the response from the Bush administration, which stood nearly alone in blaming Chavez for provoking his own removal on April 12, has been chilly. There have been no conciliatory phone calls from Washington, leaving a friendly congressional delegation to serve as an intermediary between an angry Chavez and a State Department that has never shown much tolerance for his leftist leanings or his opposition to a number of U.S. policies.

Chavez has begun his own investigation into the four days that saw him toppled, then returned to power, in a spate of political violence that left more than 60 people dead. In an interview late Friday, Chavez said "worrying details" have emerged that point to a foreign hand behind his temporary ouster -- perhaps, he suggested, one guided by the United States.

Chavez said the evidence includes information collected from a coastal radar installation that tracked a foreign military ship and aircraft operating in and over Venezuelan waters a day after his ouster. The ship, helicopter and plane -- identified by their transponder codes as military -- disappeared from the radar the morning he returned from his imprisonment on the island of La Orchila, he said.

In addition, Chavez said, an American was involved in what he characterized as an assassination plot against him uncovered in Costa Rica four months ago. He said the details of the plan revealed at the time essentially predicted what transpired on April 11, when a protest march on the presidential palace turned violent and led to his arrest by senior military officers.

"I am being objective about this. I can't be launching accusations and I want to believe that a government that has stood so strongly behind democracy is not involved in this tyrannical, macabre coup," Chavez said in the interview at the presidential palace. "It is very important to clarify these matters as soon as possible."

Those concerns, expressed during a one-hour interview that focused primarily on Venezuela's post-coup relationship with the United States, are the most pointed comments Chavez has made on the subject. Regardless of whether Chavez's inquiry or another by the Senate Intelligence Committee discovers a U.S. connection to the coup, Chavez's irritation with Washington suggests that a difficult fence-mending period lies ahead for the United States and its third-largest oil supplier.

In the months before the coup, members of Venezuela's opposition met with U.S. officials here and in Washington on several occasions. Those meetings involved some of the business leaders and military officials who ended up in the short-lived provisional government, which lost the support of the military on April 13, a day after dissolving the national legislature and the constitution.

U.S. officials said they unequivocally discouraged a coup in these meetings, and instead suggested a constitutional course to remove Chavez, such as a national referendum.

When Chavez was pushed from office, however, the Bush administration appeared to send a different message. Seventeen people were killed during the April 11 protest march, and the Bush administration echoed opposition members who accused Chavez of provoking the violence.

Chavez called the march on the palace illegal in the Friday interview, and said it was the culmination of a plot hatched last year with the help of foreign sponsors to end his three-year presidency.

As evidence, the president talked for the first time about an alleged plan to assassinate him. Chavez said he was vacationing with his family in Barinas province in western Venezuela when he received a phone call from his foreign minister, Luis Alfonso Davila, on Jan. 1 telling him to return to Caracas immediately.

When he arrived, Chavez said, Davila told him that a man from a Central American country had appeared at the Venezuelan Embassy in San Jose, Costa Rica. Chavez said the man told Venezuelan officials that he was a mercenary who had been training with perhaps a dozen other men in a Central American country for a mission scheduled for this year. The men had gathered in San Jose to await an American member of the team, who over drinks on New Year's Eve said, "Chavez is done. He doesn't know what's coming."

"This was when the guy discovered what mission he was a part of," Chavez said. "And this mission had all the parts we saw on that day [April 11] -- sharpshooters, street violence. This guy said that the plan was to take advantage of public protests, to draw blood and end my presidency."

Chavez refused to provide further details of the alleged assassination plot, including what country the informant was from or where he is now. He said he did not know whether the American was a government official or a private mercenary.

The U.S. government has strenuously denied any involvement in the coup's planning or execution. A Bush administration official said today that a review was underway to determine what U.S. warships were off the coast of Venezuela on April 13, and to account for their movements.

"We're very particular about territorial waters, very careful about those things," the official said. "Right now we're just trying to move ahead" with Chavez.

After being accused of orchestrating the April 11 violence himself, Chavez has a clear motive for presenting an alternate theory for what caused the deaths that day. The results of the criminal investigation into who opened fire and the hearings by the National Assembly on how the coup unfolded will have a bearing on his administration's legitimacy, which many opposition members say was lost when the shooting broke out.

Some Chavez supporters have been identified as being among those participating in the gunfight on the streets near the national palace.

But Chavez said members of the military unit responsible for guarding the president arrested four foreigners who were firing on the crowd from the Hotel Ausonia, less than a block from the presidential palace. Chavez said the men, who were found with high-powered rifles, were released the next day by the provisional government. Police have said that at least five of those killed were shot in the head from above.

"I have no doubt that I would have been killed had I gone out into the streets that day -- Chavez killed by a bullet from the people," he said. "That was the idea behind this. This march was looking for deaths."

The president's accusations suggest that some of the old, strident Chavez is replacing the recently chastened one. In the days after his jubilant return, the former army paratrooper who waged his own unsuccessful coup against a democratic government a decade ago had the look of a chronic speeder who had narrowly averted a fatal collision. He pledged to go slower in the future.

Chavez has made minor changes in his cabinet, and major changes at the state oil company where managerial unrest spawned the national strike that led to his ouster. And he has invited local governments, business groups and the Roman Catholic church -- institutions long ignored by his government -- to participate in a "national dialogue."

But Chavez continues to argue that his ouster was organized by a tiny group of powerful Venezuelans, and that his return on a tide of popular protest and a change of heart within the military is a truer expression of the public's will. As a result, he said, he plans to change -- in tone and style, at least.

Chavez, who was cashiered from the army after his failed coup, has pledged not to wear his combat uniform after donning it in his office the day of his ouster for the last time. Doing so riled more senior military officers for years. He gave his combat boots away while imprisoned, he said, "as a gesture of peace."

"It's not just me that has to change, though, but the entire country," Chavez said. "This is what I'm asking for -- that businesses go back to their places, that the Catholic church does the same, and most of all the media. If the media hadn't pushed these events, they never would have happened."

Since his return, Chavez has spoken to a number of world leaders, including Cuba's Fidel Castro, Mexico's Vicente Fox, Spain's Jose Maria Aznar and Russia's Vladimir Putin. All offered their congratulations, he said. But Chavez has yet to hear from any State Department official more senior than Ambassador Charles Shapiro.

President Hugo Chavez of Venezuela says ouster was an attempt on his life.