NEW YORK - New York has tried for years to solve one of its most stubborn and visible problems: tens of thousands of homeless people a night packed into shelters and thousands of others camped out on sidewalks and subways and in bus stations.

Mayor Bill de Blasio questioned aloud whether the problem of homelessness even can be solved as he unveiled a latest proposal with a decidedly modest goal. His $300 million plan would open 90 new shelters in five years and ultimately shrink the homeless population by 2,500, a mere 4 percent.

"I, today, cannot see an end" to homelessness, he said this week. "But I do believe we can do better."

The Democratic mayor's latest plan is less about emptying shelters than improving conditions for the city's more than 60,000 homeless people, and some advocates for the homeless give him credit for an approach they see as realistic.

"We have to stop promising New Yorkers that homelessness is going to end overnight," says Christine Quinn, a Democratic former City Council speaker who runs shelter operator WIN and ran against De Blasio in 2013.

But others argue the city should focus more on helping people move out of shelters rather than opening more of them.

"People really, at this point, need permanent housing, and they're talking about keeping people in the shelter system," said Charmel Lucas, who's involved with the advocacy group Picture the Homeless and knows that need firsthand.

Lucas and her partner, both freelancers for a delivery company, have been in city shelters since 2012's Superstorm Sandy displaced them and a subsequent city-paid hotel stay ended. Their efforts to get housing aid have hit roadblocks, she said, so the city instead pays thousands of dollars a month citywide. A shelter unit averages $150 a night for them to live in a room with no kitchen and a shared bathroom.

"None of it makes any sense," she said.

While homelessness has declined nationally in this decade, it has grown in such cities as New York and Los Angeles, for reasons likely tied to rents surging ahead of incomes.

New York City is legally obligated to provide shelter to any homeless person who seeks it, with eligibility rules for families. The shelter population here has jumped by about 70 percent in a decade, hitting unprecedented peaks. Another 2,800 people were living on the streets at last count last year, though advocacy groups have long believed the annual census is low.

Former mayor Michael Bloomberg pledged unsuccessfully to reduce homelessness by two-thirds. De Blasio, who took office in 2014, has previously tried approaches that ranged from a shelter repair program to daily street canvasses that he says have persuaded nearly 700 people so far to come into shelters.

De Blasio says his latest plan is "bigger and stronger and better", for both homeless people and taxpayers. He also stresses that his administration is trying to help homeless people get permanent housing, including with rental aid he says has helped 51,000 people so far get or stay out of shelters.