In an official address to U.S. Senate Intelligence Committee members Thursday, Central Intelligence AgencyDirector John Brennan said Islamic State militants are attempting to deploy operatives for further attacks on the West, and will rely more on guerrilla-style tactics to compensate for their recent territorial losses.

Brennan has led the CIA since 2013. He said ISIL militants have been working to direct and inspire attacks against its foreign enemies, as in the recent attacks in Paris and Brussels, often encouraging so-called lone wolf assaults.

"ISIL has a large cadre of Western fighters who could potentially serve as operatives for attacks in the West," Brennan said.

CIA is not just a counterterrorism agency, he said in his remarks. "We are a comprehensive intelligence service with a global charter, and we are called upon to address the full range of 21^st century threats."

But Brennan admitted he has never seen a time when the United States faced such a wide variety of threats to national security. "Run your fingers along almost any portion of the map from the Asia Pacific to North Africa, and you will quickly find a flashpoint with global implications," he said.

"China is modernizing its military and extending its reach in the South China Sea. North Korea is expanding its nuclear weapons program. Russia is threatening its neighbors and aggressively reasserting itself on the global stage. And then there is the cyber domain, where states and sub-national actors are threatening financial systems, transportation networks, and organizations of every stripe, inside government and out."

"As we have seen in Orlando, San Bernardino and elsewhere, ISIL is attempting to inspire attacks by sympathizers who have no direct links to the group," Christian Science Monitor attributed to Brennan.

Brennan referred to the June 12 Orlando attack as a "heinous act of wanton violence" and an "assault on the values of openness and tolerance" that define the United States as a nation.

He called ISIL a "formidable adversary," but said the U.S.-led coalition has progressed in combats with the group, which has led to them surrendering big swaths of territory in Iraq and Syria. They also have lost some of their leaders in airstrikes. ISIL has struggled to replenish its ranks of fighters, Brennan said, because fewer of them are traveling to Syria and others have defected.

However, the CIA leader believes ISIL is cultivating its various branches into an interconnected network.

ISIL is trying to increase its influence in Africa, he said. The ISIL branch in the Sinai has become the "most active and capable terrorist group in Egypt," attacking the Egyptian military and government targets in addition to foreigners and tourists.

Other branches have struggled to gain traction, Brennan concluded, due to factionalism and competition.

He said while the ISIL group's ability to raise money also has been curtailed, they still generate tens of millions of dollars in revenue each month, mostly from taxation and from sales of crude oil.

"Unfortunately, despite all our progress against ISIL on the battlefield and in the financial realm, our efforts have not reduced the group's terrorism capability and global reach," Brennan said.

"In fact, as the pressure mounts on ISIL, we judge that it will intensify its global terror campaign to maintain its dominance of the global terrorism agenda."