WASHINGTON (Nexstar) — The acting secretary of the Department of Homeland Security was pressed by senators Thursday about the clashes between federal officers and protesters in Portland and why those officers are in other cities around the country.

Chad Wolf defended the use of federal agents in Portland. He said they don’t target peaceful protesters and only go to cities where they’re needed. Those agents, he said “are properly trained” and “follow established law enforcement procedures and practices.”

Homeland Security is not cracking down on protesters, Wolf said, and is only engaging with violent rioters who have hurt hundreds of federal officers.

“Civil law enforcement officers were abandoned due to the dangerous policies by local officials,” he said.

He added the officers seen beating a Navy veteran were not DHS agents, and that DHS agents sent to other cities are there to fight violent crime and not to engage with protesters of any kind.

But California Sen. Kamala Harris pressed Wolf about whether those deployments are politically motivated.

“Have you discussed the deployment of DHS agents to protests in connection with the president’s re-election effort? With the president or any of his staff?” Harris asked.

“Again,” Wolf said, “I’m not going to comment on any of my conversations with the president.”

Nevada Sen. Jacky Rosen said it would be better for federal agents to focus on fighting white supremacy, which led to the mass shooting in El Paso one year ago this week.

“According to the FBI, white supremacists are the nation’s most significant domestic threat,” Rosen said.

Wolf said Homeland Security is working on both problems.