Foreign adversaries and terrorist groups are sharpening their aim at the United States—in an "increasingly concerning" way, FBI Director Christopher Wray said in a speech on Tuesday.

At the American Bar Association luncheon in Washington, D.C., Wray said the agency is working to prevent a coordinated attack from terrorist groups such as ISIS-K, an affiliate of ISIS, ABC News reports.

"Foreign terrorists, including ISIS, al-Qaida and their adherents, have renewed calls for attacks against Jewish communities here in the United States and across the West in statements and propaganda," Wray said. "The foreign terrorist threat and the potential for a coordinated attack here in the homeland, like the ISIS-K attack we saw at the Russia Concert Hall a couple weeks ago, is now increasingly concerning. Oct. 7 and the conflict that's followed will feed a pipeline of radicalization and mobilization for years to come."

The warning comes as experts predict ISIS will try to carry out an attack on the United States.

"We should believe them when they say that. They're going to try to do it," retired Gen. Frank McKenzie told ABC News' "This Week" co-anchor Martha Raddatz last month.