During his interview with President Trump that aired on Monday night on Fox News, Tucker Carlson got the president to weigh in on a topic that he and other Fox News hosts have devoted copious amounts of airtime to lately—homelessness in largely Democratic-run cities and states.

And, according to Trump, the homeless problem is a rather recent phenomenon.

Noting that they were in Japan during the president’s visit to the G-20 summit, Carlson contrasted the cleanliness of their metro areas to large American cities, adding that “there is no graffiti” or people “going to the bathroom on the streets” in Japan.

After the president mildly protested that only “some of our cities” are like that, the Fox News star said that New York City, San Francisco and Los Angeles all “have a major problem with filth.”

“Why is that?” Carlson wondered aloud.

“It’s a phenomenon that started two years ago,” Trump declared. “It’s disgraceful. I'm going to maybe—I am looking at it very seriously.”

After seemingly claiming homelessness in America only arose over the past 24 months, the president went on to suggest that police officers are getting sick simply by walking near homeless people—likely referencing reports that some Los Angeles police officers have shown signs of typhoid fever. The officers all work in a precinct that was recently fined for unsanitary working conditions.

“You can’t have what’s happening—where police officers are getting sick just by walking the beat,” he exclaimed. “I mean, they’re getting actually very sick, where people are getting sick, where the people living there are living in hell, too."

While stating that mental illness is part of the reason for homelessness, Trump went on to blame the “liberal establishment” for exacerbating the problem before claiming he “ended it very quickly” in Washington, D.C., when he became president. Homelessness has been falling in D.C. steadily for the past three years.

Trump, meanwhile, groused about the situation in San Francisco, pointing out that he owns property there and that there were areas “that you used to think as very special” but have now become “terrible.”

“So we’re looking at it very seriously,” Trump added. “We may intercede. We may do something to get that whole thing cleaned up. It’s inappropriate.”