New York Mayor Bill de Blasio on Tuesday issued a bold guarantee of affordable health care for every resident, thrusting the nation's largest city to the forefront of debates over universal health coverage and immigrant rights.

The promise is aimed at 600,000 New Yorkers who lack insurance because they can't afford it, believe they don't need it or can't get it because they are in the country illegally. The announcement makes New York the second U.S. city to attempt to provide health care to everyone living there, coming about a dozen years after San Francisco pioneered the idea with a more limited promise.

And as the Trump administration erodes the Affordable Care Act, the mayor's promise is the most ambitious of a spate of Democratic efforts to protect and expand the law's insurance gains and consumer protections at the local and state level.

De Blasio's $100 million commitment was laden with political significance. He delivered it hours before a prime-time speech by President Donald Trump, who is expected to defend his assertion the country faces a crisis of illegal immigration,

"I refuse the notion that these folks don't deserve health care," de Blasio, a Democrat, said of undocumented immigrants. "It is not only the morally right choice, but it will save taxpayers in the end."

The initiative also coincides with the start of the 2020 presidential election cycle as calls for universal coverage - often called Medicare for All - are emerging as a rallying cry among potential Democratic aspirants.

New York's plan is likely to become a marker as the long-standing debate over how large a role the government should play in health care continues to evolve - with liberals now framing it as a human right. In his remarks, de Blasio was clear where he stands. "From this moment on in New York City, everyone is guaranteed the right to health care. Everyone."

The mayor announced the plan the day after a Democrat on the other side of the country, California Gov. Gavin Newsom, also staked out an aggressive stance. On the day he was sworn into office, Newsom proposed that undocumented immigrants be eligible for Medi-Cal, the state's version of Medicaid, to age 26 - instead of the current 19. And he called for the state to provide insurance subsidies to people with higher incomes than the ACA allows.

Under NYC Care, as the city's program is being called, uninsured New Yorkers will be able to call a central phone number to get an insurance card and be assigned a doctor, giving them access to primary care and an array of specialty services, the mayor said. The services won't be free for everyone: Fees will be assessed on a sliding scale, depending on income.

De Blasio estimated that the city would spend about $100 million a year once the program is fully operating, in about two years.

The premise is that it will be more cost-effective to give people regular medical care than to rely on hospital emergency rooms to treat serious health problems that could have been addressed at far less expense earlier.

During a news conference at a Bronx hospital that is part of the city's network of public hospitals and clinics, de Blasio said repeatedly that he would prefer a federal or state single-payer health care system. But he said he hoped the city's move would mobilize broader health care changes.

"We are not going to fall for the trick of waiting for Washington, D.C., to solve our problems," the mayor said. "We are going to solve our own problems."

Starting immediately, the city will rely on its own public insurance program, known as MetroPlus, to try to attract about 300,000 uninsured residents eligible for coverage. The mayor and aides said those residents tend to be healthy young adults who think they do not need insurance, and others who cannot afford insured offered through their jobs, or the Affordable Care Act.

Starting this summer, the city officials said, they will work to enroll undocumented residents through New York City Health + Hospitals, a network of public hospitals and clinics across the five boroughs. Patients will be matched with a primary care physician and guaranteed an appointment within a week or two. Unlike most health coverage, however, the care will be available only within New York City.

The mayor portrayed this guarantee of health care as a sequel to insurance gains the city has made through the ACA. He and aides said that 8 million New Yorkers have health insurance, including 130,000 with health plans sold through a state-run marketplace created under the law. Since 2013, the city's uninsured rate has dropped by nearly half.

The plan also rests on recent efforts to strengthen the shaky finances of the NYC Health + Hospitals system, which nevertheless "still faces substantial financial challenges," according to a forecast last month by the New York City Independent Budget Office.