In an exclusive interview, CIA Director John Brennan conceded to NBC’s Richard Engel that there are more terrorists in the world than ever before –- but said the U.S. is still safer than it’s ever been since 9/11.

When Engel asked Brennan, “Are there more terrorists … out there right now than there were several years ago?” Brennan agreed that there were. “This is a much larger number than we have seen previously,” he said. He cited the growth of ISIS in Syria and Iraq and the “vast flow” of foreign fighters into the terror group’s territory, as well as the rise of ISIS “franchises” in other parts of the world.

But when Engel asked if the rise in the number of terrorists meant the U.S. was less safe than it had been, Brennan said the U.S. had actually become safer.

“When I think about 9/11 and how al Qaeda was able to take advantage of vulnerabilities within the homeland … we have strengthened our security in the homeland to a great, great degree… We as a country are far, far safer now than we were on 9/11.”

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Engel asked how Brennan could make that statement given the rise of ISIS. The CIA director said other countries were less safe because of the threat of ISIS, but reiterated his belief that the U.S. is “safer today than it was 15 years ago.”

One of the reasons the CIA director could make the assertion is that al Qaeda, the organization that attacked New York and Washington, D.C. in 2001, has been “methodically dismantled,” in his words.

The first page of the final "kill list" prepared for President George W. Bush in June 2008. Two of the people on this page, bin Laden and Shaykh Sa'id al-Masri, have been killed in the years since. Only two, including al Qaeda co-founder Ayman al-Zawahiri, remain at large.

“It took a rather intense and deliberate effort on the part of the CIA as well as other agencies and our partners overseas,” said Brennan, “to take that organization apart bit by bit. … The organization has been hollowed out.”

NBC News has exclusively obtained a top secret presidential “kill list” from June 2008, and an analysis of the list shows just how many al Qaeda targets have been taken off the battlefield in recent years.

According to a senior U.S. intelligence official, the color-coded 32-page list was prepared for President George W. Bush, and was the last list presented to him.

Twenty-eight of the 285 names on the roster of "Major Terrorism Figures" were labeled as dead when the list was published.

Former al-Qaeda leader Osama bin Laden at an undisclosed place inside Afghanistan. AFP - Getty Images, file

Eight years later, according to an NBC News analysis, 31 more terrorists on the list have been killed, 25 during the Obama administration. The most active period of what one senior intelligence official called a “slow-motion manhunt” was before and after the Abbottabad raid of May 2011 that killed Osama bin Laden. Seven leaders were killed between April and September 2011, including bin Laden.

Since 2008, other top al Qaeda figures who were not on the list have been taken out, including U.S.-born radical cleric and al Qaeda recruiter Anwar al-Awlaki.

Seven potential successors to bin Laden have been killed, including the group’s new number two, Nasir al-Wuhayshi. Nineteen of the 22 men indicted in the East Africa embassy bombings have been killed or captured and convicted, and more than half of the members of the al Qaeda Shura Council, its governing body circa 2000, have been killed or captured.

An image grab taken from a video released by ISIS official Al-Raqqa site on Sept. 23, 2014, allegedly shows ISIS recruits riding in armed trucks in an unknown location. AFP - Getty Images File

The Obama administration uses similar so-called “kill lists,” though they are described by a senior intelligence official as “less cartoonish” than the Bush version. And the U.S. continues to strike and kill targets on the list.

“They still have a lethal capability that we cannot ignore,” said Brennan of al Qaeda. “But much of that organization has been taken apart and they don’t have the numbers or the capability to carry out the attacks that they once did because of these efforts.”