With Al-Qaeda and its affiliates recruiting American citizens to carry out attacks in the country, the US will for the first time include the threat posed by radicalised, homegrown terrorism into its national security strategy.
John Brennan, deputy national security adviser for counter-terrorism and homeland security, said the Obama administration would add combating homegrown terrorism to its new strategy, which will be unveiled tomorrow.
"We've seen an increasing number of individuals here in the United States become captivated by extremist activities or causes," Brennan said at the Center for Strategic and International Studies.
"The president's national security strategy explicitly recognises the threat to the United States posed by individuals radicalised here at home," he said.
His comments assume significance in the wake of the arrest of Faisal Shahzad, the Pakistani-American, for plotting the failed Times Square bombing. He has admitted to attending a terrorist training camp in Pakistan's Waziristan tribal region.
Brennan said the US has seen a number of people who were inspired by the extremist ideologies or causes.
"(The examples are) Somali Americans from Minnesota travelling to fight in Somalia, the five Virginia men who went to Pakistan seeking terrorist training, David Headley, the Chicago man charged with helping to plan the Mumbai attacks, the Pennsylvania woman, JihadJane, charged with conspiring to murder a Danish cartoonist," he said.
He also noted that more than 20 individuals in the US have been arrested and charged with terrorism crimes, their plans and plots disrupted since the Obama Administration assumed office in January 2009.
This includes Najibullah Zazi, who planned to attack the New York subway system in what could have been the worst terrorist attack on our soil since 9/11.
Brennan said the the US is at war with Al-Qaeda and its terrorists allies, who continue to plot against America and its allies along the border regions and inside of Pakistan.
"The United States of America is at war. We are at war against Al-Qaeda and its terrorist affiliates...That is why he has refocused our efforts on Afghanistan, where Al-Qaeda continues to plot from the tribal regions along the border with Pakistan and inside of Pakistan," he said.
"We will deny Al-Qaeda and its affiliates safe haven. We will secure the world's most dangerous weapons, especially the nuclear materials that Al-Qaeda seeks and would surely use against us."