U.S. President Donald Trump says his administration plans to cite the city of San Francisco for violations of environmental regulations in connection with its homeless population.

Speaking to reporters on Air Force One late Wednesday, Trump said waste in the city's storm sewers was causing what he called tremendous pollution to flow into the ocean.

"It's a terrible situation - that's in Los Angeles and in San Francisco," he said. "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."

He said the action would be done through the Environmental Protection Agency and would come in about a week.

Trump has seized on the issue of homelessness in California cities, criticizing places like San Francisco and Los Angeles as "destroying themselves."

Feinstein: Right problem, wrong solution

Senator Dianne Feinstein, who represents California, said that while Trump is right about homelessness being a problem in the state, he is wrong in his explanation of the situation and his proposed actions would only make it worse.

"In fact California cities and the state government are devoting billions of dollars and immense energy to tackle this problem. The federal government could help that effort," she said in a statement.

Feinstein called on Trump to endorse legislation that would pair money for housing with health and job services.

"These supportive housing models are the best way to address the factors that cause homelessness," she said.

California Governor Gavin Newsom also encouraged Trump to support housing voucher programs and faulted the Trump administration for proposals to cut public housing and other aid programs.