The new head of Chicago's FBI office said Monday he'll look for ways his agents can do more to help stem homicide rates and other violent crimes in the nation's third-largest city, though he added it's not yet clear what more the FBI can do that it's not already doing.

Robert Holley's comments to the Associated Press in one of his first interviews since assuming his new post a month ago come amid calls by Mayor Rahm Emanuel, Illinois' two US senators and others for federal law enforcement to do more to combat violence in Chicago, which has hundreds of homicides each year.

Already, about 25% of Chicago agents work violent-crime cases, Holley noted. But given congressional spending constraints, shifting more resources to the gang, gun and drug crimes that underpin much of the violence could jeopardize other investigative priorities in Chicago, including corruption, counterterrorism and cybercrime, he said.

"Could I move resources from one investigative branch to another? I could," said Holley. "But I would have to take away from other programs, and I don't know if I am willing to accept that risk right now."

Holley declined to say exactly how many agents in Chicago were assigned to counterterrorism, but he said a greater number is devoted to violent crime.

Monday was the first time Holley weighed in publicly on the topic. The newly sworn-in US attorney for Chicago, Zachary Fardon, has faced similar questions.

Holley said he hasn't yet met with Emanuel about any added role for the FBI in tackling violent crime. But he said he has broached the subject with Fardon, as well as with Chicago Police Superintendent Garry McCarthy.

Chicago's killings topped 500 last year – the first time it hit that mark since 2008. Though the homicide rate has declined in 2013, some shootings, including the slaying early this year of 15-year-old honor student Hadiya Pendleton a mile from President Barack Obama's South Side home, have put the issue of Chicago violence back in the national headlines.

Holley's forte is terrorism. During his 20 years with the FBI, he has held many of the agency's top counterterrorism posts and he was among the ranking agents sent to Boston to help investigate the Boston Marathon attack.

His most recent job was at FBI headquarters in Washington as deputy assistant director of the agency's counterterrorism division. His responsibilities included briefing the director of the FBI each morning on potential terror threats.

Holley grew up in Indiana, served in the military and only applied for a job with the FBI at age 36 – just a year under the cutoff for new agents. His affable but direct persona is reflected by a sticker on one wall of his corner office on Chicago's southwest side: it has the word "whining" with a red line through it.

Now that he's responsible for overseeing the gamut of criminal activity, he said he's taking his first months in Chicago to absorb as much information as possible about areas where he's had less experience, including the city's street crime. He said that will be part of his analysis about whether the office can do more than it's doing on violence.

"I really don't know what that 'more' is right now," he said.