President Obama on Saturday outlined a series of Medicare and Medicaid cuts he said would slice $313 billion in payments over 10 years so that the savings could be applied toward an overhaul of the U.S. health system.

The cuts come on top of Medicare and Medicaid revisions Obama requested earlier this year in his fiscal 2010 budget proposal; together with those cuts the White House is now proposing a total of $622 billion in Medicare and Medicaid revisions over 10 years, most of it from Medicare.

Obama used his weekly radio address to call for slowing annual Medicare payment increases to hospitals, medical device-makers, outpatient treatment facilities and other providers in order to encourage them to deliver more cost-effective care.

He also advocated cutting federal subsidies for hospitals that treat the uninsured, and paying lower prices for drugs under Medicare’s outpatient prescription drug benefit.

“These savings underscore the fact that securing quality, affordable health care for the American people is tied directly to insisting upon fiscal responsibility,” Obama said in prepared remarks. “We will fix what’s broken while building upon what works.”

Obama is attempting to enact a plan that extends medical coverage to all Americans and would put the health system under greater government control, with coverage requirements enforced through the tax system. Experts say the final cost could exceed $1 trillion.

To persuade Americans he is not a reckless spender, the president and top administration officials are insisting that the overhaul must not increase the deficit, even in the relatively short terms of five or 10 years. That puts more pressure on the White House and Congress to identify ways to pay for the plan — and to extract savings from Medicare and Medicaid, the giant government-administered health programs that cover the elderly and poor.

Obama already has proposed limiting itemized tax deductions for the wealthiest Americans in order to finance coverage to those who can’t afford it. The idea remains unpopular with many congressional Democrats.

Administration officials predicted the latest cost-cutting would extend the solvency of Medicare’s benchmark hospital insurance trust fund by seven years and reduce beneficiaries’ Medicare Part B premiums by about $43 billion over the next decade. Medicare Part B covers physician services and outpatient care.

The proposed cuts are sure to trigger strong resistance from providers, especially hospitals, which stand to lose billions of dollars in automatic pay increases and subsidies for treating low-income and uninsured patients.

White House Budget Director Peter R. Orszag said the cuts Obama identified are a way of showing how an overhaul could be financed while the Senate Finance and House Ways and Means committees write draft bills. Combined with earlier cuts, Orszag said the administration has now identified nearly $950 billion worth of savings — a figure he said is “in the ballpark of proposals floating around.”

“We wanted to put enough specificity on the table to get us in the range,” Orszag said.

Orszag said the lower federal subsidies to hospitals would be offset by the increased business the facilities will get in a reconfigured health system, as more insured people seek diagnostic tests and other forms of care.