Former New York City Mayor Rudolph Giuliani told reporters Tuesday morning that Mayor Bill de Blasio made "a very nasty comment about me" and said it indicated de Blasio's "defensiveness."

Giuliani spoke in response to remarks de Blasio made, calling Giuliani "delusional" over his record on homelessness in the city.

"When he reduces crime 65 percent, then he can criticize me," Giuliani said after an unrelated event in lower Manhattan. "I also would suggest that he not get personal. I think he made a very nasty personal comment about me. I've made no such nasty personal comment about him. And I think it indicates his defensiveness."

Giuliani said dozens of New Yorkers have approached him in recent months to complain about homeless people on the streets.

"Mayor de Blasio is not correct," Giuliani said. "The reality is, if you lived in this city when I was mayor, you knew there was a tremendous decline in homelessness, a tremendous decline in crime that continued during Mayor [Michael] Bloomberg's time, and I can't tell you how many New Yorkers who came up to me and said to me: 'Homelessness has returned to my neighborhood.'"

Earlier Tuesday, De Blasio continued to blame the city's worsening homelessness problem on the 2008 recession and skyrocketing housing costs.

Appearing with his wife on MSNBC's "Morning Joe" program, de Blasio said the economy has exacerbated a decades-old rise in the number of people living on the streets.

"The fact is, the Great Recession led to something we hadn't seen before," de Blasio said.

Host Joe Scarborough, who had delivered a blistering monologue against the mayor on homelessness last month, noted that conditions have improved.

"The economy, though, is doing better today than when you got into office," Scarborough said. "The economy's not worse, it's better."

De Blasio responded that unlike in previous recoveries, fewer people bounced back and that housing costs in New York City continue to climb.

About 57,000 people live in the city's shelters, lower than the record 60,000 who were there in December. That's still higher than the 52,000 in shelters when de Blasio took office 21 months ago.

Recent weeks have seen a marked shift in de Blasio's homeless rhetoric, including the clearing of homeless encampments and the departure of his top deputy overseeing the homelessness issue.

"What I think I have to do better is explain the origins of this problem and show people what we're doing about it," the mayor said on "Morning Joe."

Last month the former congressman turned television pundit delivered a 10-minute broadside against de Blasio and what Scarborough called the city's "social experiment" that's been "allowing a homeless epidemic to start spreading across New York again."

"The homeless are all over the city, increasingly seen all through Central Park, all over the Upper West Side," Scarborough said then.

"This is what it looked like in the '80s, in the '70s -- we're moving back to that direction."

The guest who followed de Blasio, New Jersey Gov. Chris Christie, told "Morning Joe" that "this mayor is sitting here and deluding the American people."

"Under both Mayor Giuliani and Mayor Bloomberg, we didn't see the outward manifestation of this problem the way you see it now," Christie said. "We didn't see the diminution of the quality of life like we see it now and it's these liberal policies that this mayor ran on."