Putting the acute difficulty of his new job as U.S. intelligence chief in perspective, John D. Negroponte (search) said Thursday it was the most challenging assignment he has had in 40 years of government service.

And that says quite a bit, since the 65-year-old Negroponte's last two posts were U.S. ambassador to Iraq in the midst of a bloody anti-U.S. uprising and, before that, ambassador to the United Nations when U.S. relations with the world organization were declining over the looming war to depose President Saddam Hussein.

President Bush, at a White House news conference with Negroponte at his side, gave some indication of the difficulty of his adviser's latest task, saying he would be in overall charge of all U.S. intelligence with the goal of "stopping terrorists before they strike."

Born in London, the son of a Greek shipping magnate, Negroponte has not been free of controversy in his career. As U.S. ambassador to Honduras and its military-run government from 1981 to 1985, Negroponte was suspected of a key role in carrying out the covert strategy of the Reagan administration to crush the Sandinista government in Nicaragua.

The Reagan administration's support of the anti-Sandinista Contra rebels in Nicaragua and its sale of missiles to Iran in connection with the U.S. hostages held there turned into the Iran-Contra scandal that rocked President Reagan's second term.

Honduras, itself, was accused of human rights abuses while Negroponte held the ambassador's post. Negroponte's nomination for the U.N. post was confirmed by the Senate in September 2001 only after a half-year delay caused mostly by criticism of his record in Honduras.

For weeks before his Senate Foreign Relations Committee hearing, Negroponte was questioned by staff members on whether he had acquiesced to human rights abuses by a Honduran death squad funded and partly trained by the Central Intelligence Agency.

Negroponte testified that he did not believe the abuses were part of a deliberate Honduran government policy. "To this day," he said, "I do not believe that death squads were operating in Honduras."

But Leo Valladares, a law professor who was Honduras' first human rights commissioner afterward, said, "He knew about the abuses and violations of human rights of those the United States considered subversives."

In a report in 1993, Valladares blamed a U.S.-trained battalion for the disappearance of 184 suspected leftists.

At the United Nations, Negroponte had the difficult assignment of trying to convince the U.N. Security Council to approve force against Saddam Hussein and then defending Bush's decision to invade Iraq over the objections of France, Germany, Russia and others.

He was deputy assistant for national security in the administration of Bush's father, George H.W. Bush, and then was ambassador to Mexico and to the Philippines.