Gov. Kathy Hochul threatened on Thursday to fine several hospital systems if they did not quickly reopen psychiatric wards that had closed at the height of the pandemic, saying that those units were now urgently needed to provide treatment to homeless people with severe mental illness.

“There will be fines if you don’t bring these back online, in the timetable we’re telling you,” Ms. Hochul said. “We’re done with excuses,” she said at another point during a news conference in Manhattan about steps her administration had taken to tackle mental illness.

Homeless people with severe mental illness have presented a critical problem for the Hochul and Adams administrations, as they try to calm fears about disorder and persuade people to return to offices following the pandemic. Several high-profile incidents in the subways — including the deaths of Michelle Go early last year after she was pushed onto the tracks and of Jordan Neely, a homeless man who was killed by a chokehold in May after threatening other passengers, — increased pressure for officials to get people in the middle of psychotic episodes off the streets.

Ms. Hochul and Mayor Eric Adams announced several initiatives in the last year, including directing hospitals to open more psychiatric beds and telling police and other emergency medical workers to be more proactive in responding to homeless people in distress.

Now, the governor has accused some hospitals — which she did not identify — of purposefully resisting government directives to reopen psychiatric beds. Ms. Hochul said she thought this was happening because hospital administrators believed that psychiatric care did not generate as much revenue as other lines of service did.

”Here’s what’s at stake: people’s lives,” she said, adding that restoring hospital beds would allow more homeless people with severe mental illness to get treatment, and would leave other people feeling safer.

At issue are the number of hospital beds available for short-term psychiatric hospitalizations for people in the midst of a psychotic episode. At present, a shortage of beds in New York City means that psychiatrists often have difficulty finding a psychiatric ward with space to admit new patients.

The result, hospital psychiatrists say, is that many people who have had a psychotic episode end up being discharged after a few days in a crowded emergency room, without the benefit of inpatient hospitalization for two or so weeks during which a new medication or dosage might be tried. Finding the right antipsychotic drug to treat someone’s schizophrenia, for example, can be a slow process with a fair amount of trial-and-error.

Though the shortage of psychiatric beds in New York City is decades in the making, it has grown especially acute in recent years. Many hospitals closed psychiatric wards early in the pandemic to make room for a crushing surge of Covid patients during the first wave of illness in the spring of 2020. But in the intervening three years, only some of those units have been brought back online.

Ms. Hochul said her efforts were on track to restore about 500 psychiatric beds around the state by early next year. The state’s Office of Mental Health said more than two dozen hospitals around the state had beds that remained offline — among them, seven public hospitals in New York City.

State officials said no fines have been issued to date.

The New York State Nurses Association, a union that has closely tracked the issue, said that it was hopeful that the state’s intervention could result in the reopening of several psychiatric wards. Among them are one at NewYork-Presbyterian Brooklyn Methodist Hospital and at Syosset Hospital on Long Island, part of the Northwell Health system, among others.

A spokeswoman for NewYork-Presbyterian, sent a statement that said the hospital system was “working closely with the state to reopen more beds as quickly as possible.” A Northwell spokesman said it was also planning to reopen beds.

The city’s public hospital system said it planned to reopen 200 beds by the end of the year. “We are on track to meet that goal,” the statement said.

“Too many facilities used Covid-19 as an excuse to shutter much-needed mental health beds, and the majority of those beds remain closed today,” the president of the state nurses’ association, Nancy Hagans, said in a statement. “We welcome the state taking a more active role in pushing hospitals to restore these services, so our patients can get the care they need and deserve.”

Beyond the issue of available hospital beds, Ms. Hochul said that state-funded outreach teams that she created under a new program had found housing for nearly 200 people living on the streets or in the subway system.

Those outreach teams were part of the $1 billion plan she announced earlier this year to improve the care system for people with mental illness.