WASHINGTON (CNN) -- President Barack Obama in a major counterterrorism speech Thursday defended the American drone program, saying that despite the controversies around it, the strikes are legal and save lives.
Obama said the use of lethal force extends to U.S. citizens as well. On Wednesday, his administration disclosed for the first time that four Americans had been killed in counterterrorist drone strikes overseas, including one person who was targeted by the United States.
"When a U.S. citizen goes abroad to wage war against America -- and is actively plotting to kill U.S. citizens; and when neither the United States, nor our partners are in a position to capture him before he carries out a plot -- his citizenship should no more serve as a shield than a sniper shooting down on an innocent crowd should be protected from a SWAT team," Obama said.
"America is at a crossroads" in the fight against terror, said Obama as he outlined changes in that policy that includes an all-out push to close the Guantanamo Bay detention facility in Cuba.
One of his initiatives aims to lift a moratorium on transferring prisoners to Yemen, long a volatile land but now ruled by a government regarded by the United States as a "willing and able partner." Yemenis make up a significant portion of the 166 inmates housed there.
He continued to call for engagement with Congress on aspects of national security, more transparency in the use of drones and a review of threats facing the United States.
Obama said the United States "is still threatened by terrorists, but "the threat has shifted and evolved from the one that came to our shores" on September 11, 2001.
"From our use of drones to the detention of terrorist suspects, the decisions we are making now will define the type of nation -- and world -- that we leave to our children," Obama said at the National Defense University.
His overall policy outline was for a comprehensive counterterrorism approach focused first on establishing that al Qaeda can never again launch a coordinated attack against "us or our allies."
While Obama worked to close Guantanamo early in his first term, Congress enacted significant restrictions on the transfer of detainees from the prison that made its closure impractical.
It has come under criticism because of its growing cost and a reputation as counterproductive to winning hearts and minds in fighting terror.
This year, the State Department reassigned the special envoy who had been tasked in 2009 with closing the facility and lowered the post's profile by assigning the job to the department's legal adviser's office.
"Guantanamo hasn't been a full-time job for a year," one senior administration official told CNN this year in reference to the congressional restrictions on the repatriation of detainees who have been cleared for release.
At Wednesday's daily briefing, White House press secretary Jay Carney said Obama is "considering a range of options" to reduce the prison's population. Senior officials say there is a focus on repatriating and transferring detainees.
"I would say that one of the options is reappointing a senior official at the State Department to renew our focus on repatriating or transferring those detainees," Carney said.
"We're in the process of working on that now; we're looking at candidates" who could lead the process of helping close Guantanamo, Attorney General Eric Holder said this month. "The president has indicated that it's too expensive, that it's a recruitment tool for terrorists, it has a negative impact on our relationship with our allies, and so we're going to make a renewed effort to close Guantanamo."
But with more than half the facility's inmates engaging in various forms of hunger strike, more than 20 of them being force-fed, the failure to close the facility established in 2001 is a continuing problem for the administration.
There are 86 inmates at Guantanamo who have been cleared for transfer, 56 of them from Yemen.
New dangers have emerged
Obama made the case that the al Qaeda terror network in the Afghan and Pakistan region has been weakened but that new dangers have emerged as the U.S. winds down operations in Afghanistan after more than a decade of war triggered by the 9/11 attacks.
Threats that have emerged come from al Qaeda affiliates, localized extremist groups and homegrown terrorists, like the two men suspected of attacking the Boston Marathon last month.
The administration has been considering shifting control of lethal drone operations from the CIA to the military. One senior administration official said the "military is the appropriate agency to use force," not to rule out the range of options needed to deal with threats.
By law, the military is not able to act in the covert way the CIA can in this particular arena and must answer to Congress.
In his confirmation hearing for CIA director, John Brennan expressed a desire to move the agency away from paramilitary operations
and back to traditional areas of espionage.
"The CIA should not be doing traditional military activities and operations," he said.
Obama rejected the idea of a global war on terror in favor of a more focused approach that will engage on specific networks of extremists who threaten the United States.
The administration plans to avoid operations that will cause civilian casualties and wants to work with partners in its operations.
Use of force will be part of a larger strategy to deal with instability and hostility. Obama discussed strategies for promoting democratic governance and economic development and fostering U.S. engagement around the world.
Four Americans killed overseas in counterterrorism strikes
The address built on remarks Obama made in his State of the Union address this year when he said his administration works "tirelessly to forge a durable legal and policy framework to guide our counterterrorism efforts."
It also came on the heels of confirmation hearings for members of Obama's national security team where a pitched political battle over the use of drones was waged.
At Brennan's hearing, Republican Sen. Rand Paul of Kentucky mounted a 13-hour filibuster demanding that the administration detail whether it would be legal to strike suspected American terrorists on U.S. soil.
Attorney General Eric Holder responded in a letter to Paul that the president did not have such authority.
In a letter to congressional leaders on Wednesday, Holder disclosed the administration had deliberately killed Anwar al-Awlaki, an American citizen and radical Muslim cleric who was said to be the face of the al Qaeda franchise operating in Yemen.
Holder said he was actively plotting to attack the United States, and so targeting him was justified legally and from a policy standpoint.
The letter also disclosed that three other Americans were killed overseas in counterterror strikes but that those suspected terror figures were not deliberately targeted by the United States.
In an interview with CNN Chief White House Correspondent Jessica Yellin last year, Obama said the drone issue was a daily "struggle" for him.
"That's something that you have to struggle with," he said. "Because if you don't, it's very easy to slip into a situation in which you end up bending rules, thinking that the ends always justify the means. That's not been our tradition. That's not who we are as a country."
The American public is split on where and how drones should be used, according to a March poll by Gallup.
Although 65% of respondents said drones should be used against suspected terrorists abroad, only 41% said drones should be used against American citizens who are suspected terrorists in foreign countries.
This number dips even further when the use of drones on American soil is considered. Only 25% of people said drone should be used against suspected terrorists in the United States. And when that suspected terrorist is an American citizen, the approval for using drones falls to 13%.
Most Americans still support keeping the prison open at Guantanamo Bay.
Seventy percent of respondents to a February 2012 ABC/Washington Post poll said they approve of keeping the facility open for suspected terrorists. Only 24% said it should be closed.
CNN's Elise Labott, Chris Lawrence, Barbara Starr and Dan Merica contributed to this report.