Former NYPD Commissioner Ray Kelly said Sunday he believes police-community relations can improve in Ferguson, Missouri, when the police department diversifies its ranks to reflect the city it serves.

"It makes no sense" to have a community where the population is two-thirds African-American policed by a force where only three of 53 officers are minorities, he said on ABC's "This Week."

Kelly said healing will begin with better communication in Ferguson. A grand jury there decided last week not to indict white police officer Darren Wilson in the shooting death of unarmed black teenager Michael Brown.

"It's going to be difficult. No question about it. I think that you need communication, lots of talking, and I think they have to diversify the department," said Kelly, who left his post last year and was the NYPD's long-serving commissioner.

He called on the federal government to help fund retraining in Ferguson and the hiring of more minority officers.

"I would hope that the Justice Department is going to contribute, or Homeland Security will contribute," he said.

Wilson resigned Saturday, his lawyer said. Kelly also criticized Ferguson officials for being too slow to release information in the wake of Brown's Aug. 9 shooting.

Meanwhile, former Mayor Rudy Giuliani on "Fox News Sunday" stood by previous comments about violence in black communities, though he tempered them a bit.

"More responsibility" lies with African-Americans in cooperating and interacting with the police, but officers bear "some of that responsibility," he said, adding that the NYPD assigned officers to parts of the city based on crime statistics during his two terms as mayor.

"If I had put all my police officers on Park Avenue and none in Harlem, thousands and thousands more blacks would have been killed during the eight years that I was mayor," he said. Last week on NBC's "Meet the Press," Giuliani said the spotlight shouldn't be on Wilson and Brown.

"White police officers won't be there if you weren't killing each other 70 percent of the time," Giuliani told civil rights author Michael Eric Dyson, who is black, on the program.

Dyson responded by saying Giuliani's remarks reflected a sense of "white supremacy."