Washington (CNN) -- Homegrown terrorism will be part of the United States' National Security Strategy for the first time, according to President Barack Obama's chief counterterrorism adviser, who called it a new phase of the terrorist threat.
When the Obama administration unveils its National Security Strategy on Thursday, it will be the first time any president "explicitly recognizes the threat to the United States posed by individuals radicalized here at home," National Security Adviser John Brennan said Wednesday.
The strategy acts as a blueprint for how a White House administration intends to protect Americans. In the past, it has focused mostly on international threats. But a spate of terror-related plots in the United States recently prompted the Obama administration to include homegrown terrorism in the document, Brennan said.
Earlier this month, Pakistani-American Faisal Shahzad was charged with trying to detonate a car bomb in New York's bustling district of Times Square.
U.S. Army Major Nidal Malik Hasan is suspected of fatally shooting 13 people at Fort Hood in November.
Colorado resident Najibullah Zazi, an Afghan national, pleaded guilty in February for conspiring to detonate explosives in the New York subway system.
And David Headley, an American citizen from Chicago, Illinois, is accused of providing surveillance in the Mumbai, India, terrorist attacks that killed 160 people.
"We've seen an increasing number of individuals here in the United States become captivated by extremist ideology or causes," Brennan said. "We have seen individuals, including U.S. citizens armed with their U.S. passports, travel easily to extremist safe havens, return to America, their deadly plans disrupted by coordinated intelligence and law enforcement."
Brennan, who made his comments at the Center for Strategic and International Studies in Washington, said that as the United States has strengthened its defenses against massive attacks like 9/11, al Qaeda has shown itself to be a "resilient, resourceful and determined enemy."
Brennan said al Qaeda is recruiting individuals with little training, attempting relatively unsophisticated attacks and seeking people living in the United States to launch such attacks.
"They are seeking foot soldiers who might slip through our defense," Brennan said. "As our enemy adapts and evolves their tactics, so must we constantly adapt and evolve ours."
Brennan did not provide any specific details about the president's strategy for combating al Qaeda and its affiliates, but said it "will require a broad, sustained and integrated campaign that harnesses every tool of American power, military and civilian, kinetic and diplomatic."