ASHINGTON, Feb. 24 ó George J. Tenet, director of central intelligence, said Tuesday that the world was at least as "fraught with dangers for American interests" as it was a year ago, despite the toppling of Saddam Hussein's government in Iraq and successes in dismantling the leadership of Al Qaeda.

Most worrying, Mr. Tenet said, the radical anti-American sentiments and destructive expertise used by Al Qaeda have spread to other Sunni Muslim extremists who are behind a "next wave" of terrorism that will endure "for the foreseeable future with or without Al Qaeda in the picture."

"People who say that this is exaggerated don't look at the same world that I look at," Mr. Tenet told the Senate Intelligence Committee as he presented a stark annual report on the threats that face the United States around the world. The broader terrorist threat, he said, "is not going away any time soon."

In his State of the Union address last month, President Bush described the world as having become "a better and safer place," since American forces overthrew Mr. Hussein last year.

On Tuesday, Mr. Tenet also emphasized progress in Iraq, but he noted that the postinvasion violence continued with attacks against American forces down from a peak in November but still at a high level, similar to last August's.

Mr. Tenet's public appearance before Congress was his first since the Iraq invasion last March, and it exposed him to sharp questions from senators who asked about the gap between prewar intelligence on illicit weapons with the fact that no such weapons had been found.

Mr. Tenet sought to deflect such queries, saying it was too soon to draw firm conclusions. He promised to make public the unvarnished truth about any intelligence mistakes.

Appearing with Mr. Tenet were the F.B.I. director, Robert S. Mueller III, and the director of the Defense Intelligence Agency, Vice Adm. Lowell E. Jacoby, who presented a similarly worrisome picture. Despite the killing and capture of many senior leaders in the last year, they said, Al Qaeda enjoys considerable support, has enlisted new recruits and has created "chilling plots," including signs of possible poison attacks, training pilots for suicide missions and strong indications that it is singling out the White House, the Capitol and the American transportation system for possible attacks.

Under questioning by Senator John D. Rockefeller IV of West Virginia, the top Democrat on the panel, Mr. Tenet and his colleagues all answered "yes" later in the hearing when asked specifically whether they believed that Americans were safer now than they were a year ago.

All the officials cited direct action against terrorist networks and said progress by their agencies in sharing information ought to help alert Americans about possible terrorist attacks.

Mr. Tenet and Mr. Mueller were otherwise explicit in saying that the threat to Americans had not diminished and might have increased. Terrorism poses "perhaps a more significant threat" than a year ago, Mr. Mueller said in response to a question from Senator Pat Roberts, the Kansas Republican who is chairman of the committee.

Mr. Tenet made that point on the first of 24 pages of prepared testimony.

Compared with last year, Mr. Tenet said, "the world I will discuss today is equally, if not more, complicated and fraught with dangers for American interests, but one that also holds great opportunity for positive change."

About Iraq, now the base for more than 100,000 American troops and the largest overseas American intelligence operation since the Vietnam War, Mr. Tenet said he remained concerned about a "serious threat" to American forces and to emerging institutions in Iraq, despite the success in removing Mr. Hussein and the fact that he and most of his top lieutenants were in custody.

So far, Mr. Tenet said, there are "very few" signs of coordination in the anti-American campaign between former members of Mr. Hussein's government and political party and foreign fighters like Abu Musab al-Zarqawi, a Jordanian with loose links to Osama bin Laden. Mr. Zarqawi's network was cited by the intelligence chief as a leading example of how Mr. bin Laden's message and tactics had infected Sunni Muslim extremists around the world.

"These far-flung groups increasingly set the agenda and are redefining the threat we face," Mr. Tenet said. "They are not all creatures of bin Laden, and so their threat is not tied to his. They have autonomous leadership. They pick their own targets. They plan their own attacks."

Mr. Tenet offered no clear picture of how the United States might combat the more diffuse threat from those groups, including international organizations like Ansar al-Isalm in Iraq, the Libyan Islamic Fighting Group and the Islamic Movement of Uzbekistan, as well as local ones like the Salifiya Jihadia, a Moroccan network that carried out suicide bombings last May in Casablanca.

The director said the tactical work by the intelligence agencies and military in identifying, tracking and seizing suspected terrorists needed to be backed up with a broader strategy, perhaps from within Muslim countries, to combat the ideology that "depicts the United States as Islam's greatest foe."

"We're just chasing many people all the time, and we're doing it better and better all the time," he said. Mr. bin Laden, for one, he said, was "deeper underground" than ever.

"Somebody," Mr. Tenet added, "has to get at the business of attacking this phenomena."

He described as "seriously damaged" the leadership of Al Qaeda as it was charted after the Sept. 11, 2001, attacks. But he said that the group "remains as committed as ever to attacking the U.S. mainland" and that intelligence information "continues to validate my deepest concern, that this enemy remains intent on obtaining and using catastrophic weapons."

In addition to Al Qaeda, Mr. Tenet said, more than 24 terrorist groups are pursuing chemical, biological and radiological and nuclear weapons. He said intelligence agencies now saw "a heightened risk" of poison attacks, and an increasing threat of more sophisticated attacks, including the possible use of an improvised chemical weapon in a crowded area.