President Donald Trump said the Environmental Protection Agency will be “putting out a notice” of violations in San Francisco related to its homeless population, according to The Associated Press.

Trump told reporters on Wednesday, Sept. 18, aboard Air Force One that a tremendous amount of waste, including needles, is going through storm drains into the ocean.

He said, “It’s a terrible situation that’s in Los Angeles and in San Francisco. And we’re going to be giving San Francisco—they’re in total violation—we’re going to be giving them a notice very soon.”

Trump said, “They have to clean it up. We can’t have our cities going to hell.”

Earlier, on Tuesday, the president said he could not let major California cities “destroy themselves” by failing to address homeless issues, as state and local officials seem reluctant to ask for help from the federal government to fight the ongoing housing crisis in the state,  according to Fox News.  

 “We can’t let Los Angeles, San Francisco, and numerous other cities destroy themselves by allowing what’s happening,” the president said.

“We have people living in our … best highways, our best streets, our best entrances to buildings … where people in those buildings pay tremendous taxes, where they went to those locations because of the prestige,” Trump continued. “In many cases, they came from other countries and they moved to Los Angeles or they moved to San Francisco because of the prestige of the city, and all of a sudden they have tents. Hundreds and hundreds of tents and people living at the entrance to their office building. And they want to leave. And the people of San Francisco are fed up, and the people of Los Angeles are fed up.”

President Trump said he would discuss possible solutions to California’s homeless crisis with U.S. Department of Housing and Urban Development Secretary Ben Carson. Carson also requested to meet with Los Angeles Police Department Chief Michel Moore to discuss the housing crisis, including homeless issues, Fox News reported. 

Carson said on “Fox News @ Night” on Tuesday that “we need to do something” for California homeless crisis as it might become “a major epidemic.”

“It’s a severe crisis in L.A. and in many parts of California because it’s not just a fact that people are out on the street, but you know there’s feces on the street, there are all kinds of health hazards there. And this could really blow up into a major epidemic. So we need to do something,” said Carson.

Includes reporting from The Associated Press