The director of the CIA went to Capitol Hill today to testify about the evolving threat of ISIS.

FOX's Rachel Sutherland reports from Washington:

CIA Director John Brennan told the Senate Intelligence Committee that progress has been made in the fight against ISIS, but he cautioned the group remains:

(Brennan) "Formidable, resilient and largely cohesive enemy and we anticipate that the group will adjust its strategy and tactics in an effort to regain momentum."

Brennan said he expects ISIS to rely more on guerrilla tactics, including high-profile attacks outside territory it holds and that the only way to reduce or destroy the group is to take back its real estate in Iraq and Syria.

In Washington, Rachel Sutherland, FOX News.

FOX's Rachel Sutherland on Twitter: @SutherlandFox