"Despite these successes, however the terrorist threat to the US in the homeland and abroad endures," he acknowledged.
"We know from experience that al Qaeda is a patient, persistent, imaginative, adapted, dangerous opponent - but it is vulnerable and displaced," Goss added.
"Our pursuit of al Qaeda and its most senior leaders, including (Osama) bin Laden and his deputy (Ayman) Zawahiri is intense," Goss said.
"However, that capture ... will not be enough to eliminate the terrorist threat to the US homeland and interests overseas."
Al Qaeda is, he said, "intent on finding ways to circumvent US security enhancements to strike Americans in the homeland."
Goss added that "al Qaeda is only one facet of the threat from a broader Sunni jihadist movement," warning: "It may be only a matter of time before al Qaeda or other group attempt to use chemical, biological, radiological or nuclear weapons. We must focus on that."
IRAN SEEKS LONG RANGE MISSILES:
Iran is stepping up efforts to build long range missiles and remains a "state sponsor" of terrorism, Central Intelligence Agency director Porter Goss told Congress on Wednesday.
"Iran continues its pursuit of long-range ballistic missiles," Goss said in testimony to the Senate Intelligence Committee on the main security threats to the United States.
Goss went on to reaffirm US accusations that the fundamentalist Islamic government in Tehran has strong links to militant groups.
He said that even after the September 11, 2001 attacks on the United States, "Iran continues to support terrorist groups in the region such as Hezbollah. It is a state sponsor."