WASHINGTON — Al Qaeda, increasingly tamped down in Iraq, is establishing cells in other countries as Osama bin Laden’s organization uses Pakistan’s tribal region to train for attacks in Afghanistan, the Middle East, Africa, and America, the American intelligence chief said today.

“Al Qaeda remains the pre-eminent threat against the United States,” Mike McConnell told a Senate hearing more than six years after the September 11, 2001, attacks.

Mr. McConnell said that fewer than 100 Al Qaeda terrorists have moved from Iraq to establish cells in other countries as the American military clamps down on their activities, and the organization “may deploy resources to mount attacks outside the country.”

Mr. McConnell said while the level of violence in Iraq has dropped sharply since last year, it is going to be years before Iraq is stable.

“It is not going to be over in a year. It’s going to be a long time to bring it to closure,” he said.

The Al Qaeda network in Iraq, Pakistan, and Afghanistan has suffered setbacks, but he said the group poses a persistent and growing danger.

The Pakistani tribal areas provide Al Qaeda a safe haven similar to what it enjoyed in Afghanistan before the war but on a smaller and less secure scale, Mr. McConnell told the Senate Intelligence Committee. It uses the area to “maintain a cadre of skilled lieutenants capable of directing the organization’s operations around the world,” he said.

The next attack on America will most likely be launched by Al Qaeda operating in those “under-governed regions” of Pakistan, the chairman of the Joint Chiefs of Staff, Admiral Michael Mullen, planned to tell Congress tomorrow.

“Continued congressional support for the legitimate government of Pakistan braces this bulwark in the long war against violent extremism,” Admiral Mullen stated in remarks prepared for a separate budget hearing.

American intelligence agencies believe Al Qaeda figures who fled Afghanistan after the ouster of the Taliban regime in 2001 have regrouped inside Pakistan’s tribal region, posing a threat to American forces across the border and offering a potential base for global operations. American officials have said they believe Mr. bin Laden is hiding there.

Still, Mr. McConnell lauded Pakistan’s cooperation, saying that more than 1,300 Pakistanis died fighting terrorists or in terrorist attacks in 2007. He said Islamabad has done more to “neutralize” terrorists than any other partner of America.

Despite the cooperation, the director of the Defense Intelligence Agency, Lieutenant General Michael Maples, said the Pakistani military has been unable to disrupt or damage Al Qaeda terrorists operating in the tribal border region. And the American military is prohibited by Pakistan from pursuing Taliban and Al Qaeda fighters that cross the border to conduct attacks inside Afghanistan.

Mr. McConnell also told the committee that the Taliban, once thought to be routed from Afghanistan, has expanded its operations into previously peaceful areas of the west and around the capital of Kabul, despite the death or capture of three top commanders in the last year.

The Taliban’s staying power is largely attributable to the nearly $1 billion generated in Afghanistan last year from cultivation of the poppy, the key ingredient to make opium. Poppy cultivation remains at or near record 2004 levels and much of the proceeds finance Taliban operations, the American officials said.