Washington-Central Intelligence Agency Director John Brennan has admitted that the efforts exerted by the United States and the international community in curbing the global reach of ISIS have not yet succeeded.

In a rare open hearing, Brennan gave the Senate intelligence committee an update on the threat from Islamic extremists and shared his views on a myriad of other topics, including encryption, Russia and Syria.

ISIS “has a large cadre of Western fighters who could potentially serve as operatives for attacks in the West. And the group is probably exploring a variety of means for infiltrating operatives into the West, including refugee flows, smuggling routes, and legitimate methods of travel,” he said.

He said the terrorist organization is gradually cultivating its global network of branches into a more interconnected organization. “The branch in Libya is probably the most developed and the most dangerous. We assess that it is trying to increase its influence in Africa and to plot attacks in the region and in Europe.”

The CIA estimates there are 18,000 to 22,000 ISIS fighters in Syria and Iraq — down from about 33,000 last year. The branch in Libya, with between 5,000 and 8,000 fighters, is the most advanced and most dangerous, but ISIS is trying to increase its influence in Africa, Brennan said.

The international coalition succeeded in putting ISIS on the defensive, he told the hearing, but he added that he battle against the group will be difficult and long.

Brennan stressed that ISIS appears to be a long way from realizing the vision that Abu Bakr al-Baghdadi laid out when he declared the “caliphate” two years ago in Mosul.

ISIS “has lost large stretches of territory in both Syria and Iraq. Its finance and media operations have been squeezed,” he said, adding “on the battlefields of Syria and Iraq, the U.S-led coalition has made important progress” against the group.

Meanwhile, U.S. President Barack Obama and his deputy Joe Biden traveled to grief-stricken Orlando Thursday, meeting loved ones devastated by a shooting rampage at a nightclub.

Forty-nine people were killed and 53 wounded when 29-year-old Omar Mateen ran amok in the packed nightclub early Sunday, armed with a legally bought assault rifle.

Republican nominee Donald Trump has softened his stance on arms possession.

He said on Twitter that he would meet the National Rifle Association gun lobby to discuss ways to block people on terrorism watch or no-fly lists from buying guns.